Complex Anatomy Research Articles

Robotic-assisted surgery for lateral ventral hernias - experience of robot-assisted methods for retromuscular and preperitoneal abdominal wall reconstruction.

Due to the proximity to bony structures and the complex anatomy of the three-layered lateral abdominal wall, the surgical treatment of lateral ventral hernias is technically demanding. With this study we would like to demonstrate how lateral abdominal wall hernias can be treated using new robotic surgical techniques with extraperitoneal mesh placement. The purpose of this study is to demonstrate that the application of the robot in minimally invasive treatment of lateral abdominal wall hernias is safe and efficient. A retrospective analysis of all patients who underwent robotically-assisted lateral ventral hernia repair surgery from June 2019 to December 2023 was performed. A total of 50 ventral hernias were operated robotically due to a lateral hernia in the study period. 45 patients had an incisional hernia and 5 patients a primary spighelian hernia. 27 patients had only lateral findings, whereas 23 patients had combined hernias with lateral and medial hernial defects. 18 patients were treated with a preperitoneal mesh (r-vTAPP). 31 patients required TAR to achieve complete fascial closure and sufficient mesh overlap (24 extraperitoneal approach r-eTAR/7 transperitonel approach r-TAR). One patient had to be converted intraoperatively from a planned preperitoneal mesh to an intraperitoneal mesh repair (r-IPOM). The median hernia defect area was 71cm² (3-375cm²). The median mesh size was 600cm² (150-1290cm²). The median mesh defect ratio (MDR) was 10 (2,33-133,33). Five postoperative complications were encountered (10%). Two reoperations (4%) were required. The utilization of new robotic surgical techniques provides a safe minimally invasive treatment option even for complex lateral ventral hernias that previously posed difficulties in surgical management. The early postoperative results show promising outcomes.

Relationship between characteristic values of shear strength parallel to grain and tensile strength perpendicular to grain for tropical woods

Wood, due to its complex anatomy, requires meticulous characterization that imposes several tests to be carried out to evaluate its properties. Normative codes adopt different specimens to this aim. Geometric specificities proposed by NBR 7190-3:2022 and ASTM D143-22 to specimens used for estimating wood strength in tensile perpendicular to grain (ft90) make them difficult to carry out. Thus it is advisable to consider relating ft90 with another mechanical property, for example, the shear strength parallel to the grain (fv0). This paper aims to establish a coefficient relating the characteristic values of ft90 and fv0, for strength classes D40 and D60 (frequently used for structural purposes) of Brazilian Code 7190:3-2022. A further aim, if possible, is to determine a single representative coefficient for both classes. Tests made it possible to obtain those properties for four species from each class, following NBR 7190-3:2022 guidelines. The optimal coefficient was determined using the least squares method (MMQ). Ratios ft90,k/fv0,k were 0.22 and 0.19, for classes D40 and D60, respectively. As these ratios don’t present a significant difference, it is viable to adopt a single relationship for both classes, thus simplifying characterization procedures.

Deep Quasi-Recurrent Self-Attention with Dual Encoder-Decoder in Biomedical CT Image Segmentation.

Developing deep learning models for accurate segmentation of biomedical CT images is challenging due to their complex structures, anatomy variations, noise, and unavailability of sufficient labeled data to train the models. There are many models in the literature, but the researchers are yet to be satisfied with their performance in analyzing biomedical Computed Tomography (CT) images. In this article, we pioneer a deep quasi-recurrent self-attention structure that works with a dual encoder-decoder. The proposed novel deep quasi-recurrent self-attention architecture evokes parameter reuse capability that offers consistency in learning and quick convergence of the model. Furthermore, the quasi-recurrent structure leverages the features acquired from the previous time points and elevates the segmentation quality. The model also efficiently addresses long-range dependencies through a selective focus on contextual information and hierarchical representation. Moreover, the dynamic and adaptive operation, incremental and efficient information processing of the deep quasi-recurrent self-attention structure leads to improved generalization across different scales and levels of abstraction. Along with the model, we innovate a new training strategy that fits with the proposed deep quasi-recurrent self-attention architecture. The model performance is evaluated on various publicly available CT scan datasets and compared with state-of-the-art models. The result shows that the proposed model outperforms them in segmentation quality and training speed. The model can assist physicians in improving the accuracy of medical diagnoses.

Enhancing Root Canal Therapy with NIR-II Semiconducting Polymer AIEgen and Low-Concentration Sodium Hypochlorite Synergy.

Despite significant efforts to eliminate bacterial biofilm within root canals, achieving effective disinfection remains challenging due to the complex anatomy and limitations of disinfectants. In this study, a second near-infrared (NIR-II) semiconducting polymer with aggregation-induced emission (AIE) properties, named PIDT-TBT, is deliberately designed and synthesized. This proposes an AIE luminogen-based sterilization strategy in synergy with a low concentration of sodium hypochlorite (NaClO). Water-dispersible PIDT-TBT nanoparticles (NPs) are prepared, demonstrating good biocompatibility, as well as photothermal and photodynamic properties. Subsequent antibacterial tests show that PIDT-TBT NPs exhibit excellent bactericidal effects against three bacterial strains: Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis, upon 808nm laser irradiation. In synergy with a low concentration of NaClO (0.5%) solution, PIDT-TBT NPs significantly improves the outcome of root canal treatment under 808nm laser irradiation in a human extracted tooth root canal infection model. Additionally, it is found that PIDT-TBT NPs combine with a low concentration of NaClO solution could safely dissolve dentin debris and further increase the efficiency of root canal preparation by altering the elemental composition of the inner root canal wall.

An Enhanced Approach to Intelligent Computer-Assisted Localization of Liver Tumor on Computed Tomography Images

Computed Tomography (CT) Imaging is frequently used to find liver cancer. CT imaging of the liver generates cross-sectional images of the abdominal region. The task of segmenting a liver tumor on CT images is tedious due to the anatomic complexity of the liver. Therefore, liver tumor detection has been performed manually or semi-automatically which is an exhaustive process. Further, a tumor may be present on only some slices of the CT scan and hence there is a need to automatically identify images that contain tumors from acquired CT images and then locate a region of the tumor on those images for further diagnosis. Automatic detection helps the radiologist to obtain fast, accurate, and effective results. Accordingly, in this paper, an enhanced approach is proposed based on deep learning, efficient fuzzy c-means (EFCM) clustering, and a region-based algorithm for the detection of a liver tumor. A deep learning model built on a convolutional neural network is used to identify whether the CT image contains a tumor. If it contains the tumor, then the proposed EFCM and region-based algorithms are applied to locate the tumor on the CT image. The EFCM algorithm is combined with a region-based technique to automatically determine the initial pixel and threshold values required to segment the liver tumor. The proposed method is applied to several CT abdominal images. The results of the tumor segmentation are validated by comparing them with the tumor regions detected by radiologists. The estimated results of the experiment show that the proposed technique successfully detects the liver tumor on the CT image with less than 2% relative error.

Lateral Spinal Artery Aneurysm Causing Subarachnoid Hemorrhage: Literature Review and Case Report.

Ruptured aneurysms of the lateral spinal artery (LSA) causing subarachnoid hemorrhage (SAH) are exceptionally rare. Unlike common aneurysms in the circle of Willis, LSA aneurysms present unique diagnostic and therapeutic challenges due to their complex anatomy. We reviewed the literature, examining case reports detailing LSA aneurysm occurrences, diagnoses, treatments, and complications, and our subsequent analysis highlights the clinical presentations, imaging findings, treatment methods, and anatomical features of the LSA. We identified 10 patients from 7 case reports of LSA aneurysm presenting with SAH, and combined with the present case, this comprised a total of 11 patients. An initial CT angiography identified LSA aneurysm in only 2 of 11 patients, while 5 cases were detected in transfemoral cerebral angiography. Seven patients had stenosis or occlusion of nearby arteries. Among the 10 patients treated, 7 underwent microsurgical clipping, and 3 had endovascular treatment; complications included PICA infarction and subdural hematoma. LSA aneurysms, though rare, should be considered in differential diagnoses of posterior fossa SAH. An accurate diagnosis often requires repeated imaging. It is proposed to individualize treatment strategies based on the unique anatomical structure and hemodynamic conditions of each patient, utilizing both endovascular and surgical approaches. Understanding the vascular anatomy and collateral pathways of the LSA is crucial for improving diagnostic accuracy and treatment outcomes.

An atlas of Brachypodium distachyon lateral root development.

The root system of plants is a vital part for successful development and adaptation to different soil types and environments. A major determinant of the shape of a plant root system is the formation of lateral roots, allowing for expansion of the root system. Arabidopsis thaliana, with its simple root anatomy, has been extensively studied to reveal the genetic program underlying root branching. However, to get a more general understanding of lateral root development, comparative studies in species with a more complex root anatomy are required. Here, by combining optimized clearing methods and histology, we describe an atlas of lateral root development in Brachypodium distachyon, a wild, temperate grass species. We show that lateral roots initiate from enlarged phloem pole pericycle cells and that the overlying endodermis reactivates its cell cycle and eventually forms the root cap. In addition, auxin signaling reported by the DR5 reporter was not detected in the phloem pole pericycle cells or young primordia. In contrast, auxin signaling was activated in the overlying cortical cell layers, including the exodermis. Thus, Brachypodium is a valuable model to investigate how signaling pathways and cellular responses have been repurposed to facilitate lateral root organogenesis.

Comparison of the Image Quality of Turbo Spin Echo and Echo-Planar Diffusion-Weighted Imaging of the Head and Neck Region.

Magnetic resonance imaging (MRI) of the head and neck region is notably challenging due to the complex anatomy and the critical need for high-resolution imaging to accurately diagnose various pathologies. The two prominent MRI techniques used in this context are turbo spin echo (TSE) and echo-planar diffusion-weighted imaging (EP-DWI). TSE is recognized for providing high-resolution anatomical images, whereas EP-DWI offers functional imaging that highlights the diffusion of water molecules, essential for detecting early pathological changes. This study aims to compare the image quality of TSE and EP-DWI in the head and neck region to assess their diagnostic efficacy and clinical utility. This retrospective study was conducted at Saveetha Medical College and Hospital over six months. A total of 100 patients (50 males and 50 females, aged 18-65 years) with various head and neck pathologies were included. Patients underwent both TSE and EP-DWI sequences using a Philips MULTIVA 1.5 T scanner. Image quality was assessed based on signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), artifact presence, and lesion detection. Two experienced radiologists independently reviewed the images, with inter-observer agreement calculated using Cohen's kappa coefficient. The mean SNR for TSE was significantly higher than EP-DWI (45.2 vs. 28.7, p<0.01), indicating superior image clarity and detail in TSE images. TSE demonstrated a higher mean CNR compared to EP-DWI (25.4 vs. 15.8, p<0.01), suggesting better differentiation between different tissue types and pathologies. Artifacts were more frequent in EP-DWI images (45% vs. 15%), with motion artifacts being the most common. TSE detected more lesions (120 vs. 95), with more precise delineation of lesions. The inter-observer agreement was excellent for both TSE and EP-DWI, with kappa values of 0.85 and 0.80, respectively. TSE MRI provides superior image quality compared to EP-DWI for evaluating the head and neck region. The enhanced SNR and CNR in TSE images result in clearer and more detailed visualizations of anatomical structures and pathological changes, with fewer artifacts. While EP-DWI is valuable for functional imaging, its role should be complementary to TSE. The study suggests that TSE should be the preferred modality for detailed anatomical assessment in the head and neck region. Further studies with larger sample sizes and advanced imaging techniques may provide additional insights into optimizing MRI protocols for head and neck imaging.

Multi-class segmentation of temporomandibular joint using ensemble deep learning

Temporomandibular joint disorders are prevalent causes of orofacial discomfort. Diagnosis predominantly relies on assessing the configuration and positions of temporomandibular joint components in magnetic resonance images. The complex anatomy of the temporomandibular joint, coupled with the variability in magnetic resonance image quality, often hinders an accurate diagnosis. To surmount this challenge, we developed deep learning models tailored to the automatic segmentation of temporomandibular joint components, including the temporal bone, disc, and condyle. These models underwent rigorous training and validation utilizing a dataset of 3693 magnetic resonance images from 542 patients. Upon evaluation, our ensemble model, which combines five individual models, yielded average Dice similarity coefficients of 0.867, 0.733, 0.904, and 0.952 for the temporal bone, disc, condyle, and background class during internal testing. In the external validation, the average Dice similarity coefficients values for the temporal bone, disc, condyle, and background were 0.720, 0.604, 0.800, and 0.869, respectively. When applied in a clinical setting, these artificial intelligence-augmented tools enhanced the diagnostic accuracy of physicians, especially when discerning between temporomandibular joint anterior disc displacement and osteoarthritis. In essence, automated temporomandibular joint segmentation by our deep learning approach, stands as a promising aid in refining temporomandibular joint disorders diagnosis and treatment strategies.

Outcome of primary fixation of traumatic acetabular fractures

Objectives; Traumatic acetabular fracture is a major injury with high association of mortality, morbidity and long recovery period. Surgical management of acetabular fracture is a technical challenge needing high level of skills and vigilance because of the complex anatomy and risk to surrounding structures. We aim to look at two surgical techniques for fixation of acetabular fracture and their outcome in this study. Methods; Between April 2018 and March 2023, a total of 26 patients (15 males and 11 females) were treated for acetabular fracture fixation. 10 were treated with minima invasive technique Close reduction and per-cutaneous fixation because of good reduction was achieved under image guidance and 16 patients had ORIF with use of various recon plates, screws and wires. Results; All patients were followed up for 12 months. Among all patients, the clinical outcomes were recorded as excellent in 17 patients (17/26, 65%), good in 5 (5/26, 19%), fair in 2 (2/26, 7.7%), and poor in 2 (2/26. 7.7%), according to the modified Merle d’Aubigné-Postel score. The average modified Merle d’Aubigné-Postel score was 15 ± 2.0 points (range, 10–18 points). The radio-logical healing was assessed according to the Matta score [22] and were reported excellent in 15 patients (15/26, 57.6%), good in 7 (7/26, 26.8%), fair in 1 (1/26, 3.8%),and poor in 3 (3/26, 11.5%). Conclusion; our study shows comparable clinical outcome for acetabular fracture fixation using either ORIF or CRPF technique. Right patient choice and good knowledge of anatomy is of paramount importance.

The influence of burrow-generated pseudobreccia on the preservation of fossil concentrations

Burrowed discontinuity surfaces associated with condensed fossil concentrations demarcate breaks (hiatuses) in the Phanerozoic marine sedimentary record. Such intervals may be difficult to interpret in view of complex anatomy and varied fossil signatures. Transformation of a discontinuity surface into a heavily burrowed ‘pseudobreccia’ may further complicate the record, but this issue has remained unexploited to date. The richly fossiliferous Cretaceous–Paleogene (Maastrichtian–Danian) boundary interval exposed in Poland provides opportunities to test the influence of burrow-generated pseudobreccia on the preservation of associated hiatal fossil concentrations. Here, we document pseudobreccia anatomy and fossil-sediment relationships by three-dimensional X-ray computed tomography imaging. In the pseudobreccia zone, we identify a distinctive assemblage of late Maastrichtian fossils, which underwent subsurface preparation by burrowers in a hitherto unreported ichno-taphonomic process. Recognition of pseudobreccia is a prerequisite for the interpretation of the stratigraphy, sedimentology and fossil record of such intervals, which is of special interest for periods of major biotic turnovers, like the end-Cretaceous mass extinction.

Efficacy of endovascular treatment for distal anterior cerebral artery aneurysms: A multicenter observational study

ObjectivesDistal anterior cerebral artery (DACA) aneurysms account for 1%-9% of all intracranial aneurysms. Microsurgical treatment is generally preferred for DACA aneurysms; however, it presents challenges owing to the anatomical complexities. Advances in neuro-interventional techniques have yielded promising results. This study aims to compare the clinical outcomes of DACA aneurysms treated with microsurgery and endovascular treatment (EVT) to elucidate the efficacy of EVT. Materials and MethodsA multicenter observational registry comprising 16 stroke centers was utilized for this study. Data was retrospectively and prospectively analyzed from 166 patients with DACA aneurysms in our database, which included 4,552 consecutive patients with ruptured or unruptured intracranial aneurysms who underwent microsurgical or endovascular treatment between January 2013 and December 2021. ResultsSurgical clipping was performed in 115 patients, and 51 underwent coil embolization. The median follow-up duration was 15.3 months. No significant differences were observed in patient characteristics between the two treatment modalities. There were no differences in complication-related morbidity between the microsurgical treatment and EVT groups in either unruptured (10.5% vs. 9.1%, p=1.00) or ruptured aneurysms (5.2% vs. 6.9%, p=0.66). Coil embolization resulted in higher recurrence and retreatment rates than surgical clipping did, especially for ruptured aneurysms (2.6% vs. 27.6%, p<0.01). ConclusionsEndovascular treatment is an alternative to microsurgery for DACA aneurysms especially in unruptured cases or the patients who have difficulty undergoing craniotomy due to their general condition, albeit with considerations for higher recurrence and retreatment rates, particularly in ruptured cases. Close follow-up is crucial for the effective management of these challenges. Further studies are needed to refine the treatment strategies for DACA aneurysms.

Comparative muscle anatomy of the anuran pelvis and hindlimb in relation to locomotor mode.

Frogs have a highly conserved body plan, yet they employ a diverse array of locomotor modes, making them ideal organisms for investigating the relationships between morphology and locomotor function, in particular whether anatomical complexity is a prerequisite for functional complexity. We use diffusible iodine contrast-enhanced microCT (diceCT) imaging to digitally dissect the gross muscle anatomy of the pelvis and hindlimbs for 30 species of frogs representing five primary locomotor modes, including the first known detailed dissection for some of the world's smallest frogs, forming the largest digital comparative analysis of musculoskeletal structure in any vertebrate clade to date. By linking musculoskeletal dissections and phylogenetic comparative methods, we then quantify and compare relationships between anatomy and function across over 160 million years of anuran evolution. In summary, we have found that bone lengths and pelvic crest sizes are generally not reliable predictors of muscle sizes, which highlights important implications for future palaeontological studies. Our investigation also presents previously unreported differences in muscle anatomy between frogs specialising in different locomotor modes, including several of the smallest frog hindlimb muscles, which are extremely difficult to extract and measure using traditional approaches. Furthermore, we find evidence of many-to-one and one-to-many mapping of form to function across the phylogeny. Additionally, we perform the first quantitative analysis of how the degree of muscle separation can differ between frogs. We find evidence that phylogenetic history is the key contributing factor to muscle separation in the pelvis and thigh, while the separation of shank muscles is influenced more strongly by locomotor mode. Finally, our anatomical 3D reconstructions are published alongside this manuscript to contribute towards future research and serve as educational materials.

Does adding sacroiliac (type IV) resection to periacetabular (type II) resection increase complications or provide worse clinical outcomes? An institutional experience and systematic review

Background and objectivesInternal hemipelvectomy is a limb sparing procedure most commonly indicated for malignant bone and soft tissue tumors of the pelvis. Partial resection and pelvic reconstruction may be challenging for orthopedic oncologists due to late presentation, high tumor burden, and complex anatomy. Specifically, wide resection of tumors involving the periacetabular and sacroiliac (SI) regions may compromise adjacent vital neurovascular structures, impair wound healing, or limit functional recovery. We aimed to present a series of patients treated at our institution who underwent periacetabular internal hemipelvectomy (Type II) with or without sacral extension (Type IV) in combination with a systematic review to investigate postoperative complications, functional outcomes, and implant and patient survival following pelvic tumor resection via Type II hemipelvectomy with or without Type IV resection. Materials and methodsA surgical registry of consecutive patients treated with internal hemipelvectomy for primary or secondary pelvic bone tumors at our institution since 1994 was retrospectively reviewed. All type II resection patients were stratified into two separate cohorts, based on whether or not periacetabular resection was extended beyond the SI joint to include the sacrum (Type IV), as per the Enneking and Dunham classification. Patient demographics, operative parameters, complications, and oncological outcomes were collected. Categorical and continuous variables were compared with Pearson's chi square or Fisher's exact test and the Mann-Whitney U test, respectively. Literature review according to PRISMA guidelines queried studies pertaining to patient outcomes following periacetabular internal hemipelvectomy. The search strategy included combinations of the key words “internal hemipelvectomy”, “pelvic reconstruction”, “pelvic tumor”, and “limb salvage”. Pooled data was compared using Pearson's chi square. Statistical significance was established as p < 0.05. ResultsA total of 76 patients were treated at our institution with internal hemipelvectomy for pelvic tumor resection, of whom 21 had periacetabular resection. Fifteen patients underwent Type II resection without Type IV involvement, whereas six patients had combined Type II/IV resection. There were no significant differences between groups in operative time, blood loss, complications, local recurrence, postoperative metastasis, or disease mortality. Systematic review yielded 69 studies comprising 929 patients who underwent internal hemipelvectomy with acetabular resection. Of these, 906 (97.5 %) had only Type II resection while 23 (2.5 %) had concomitant Type II/IV resection. While overall complication rates were comparable, Type II resection alone produced significantly fewer neurological complications when compared to Type II resection with sacral extension (3.9 % vs. 17.4 %, p = 0.001). No significant differences were found between rates of wound complications, infections, or construct failures. Local recurrence, postoperative metastasis, and survival outcomes were similar. Type II internal hemipelvectomy without Type IV resection on average produced higher postoperative MSTS functional scores than with Type IV resection. ConclusionIn our series, the two groups exhibited no differences. From the systematic review, operative parameters, local recurrence or systemic metastasis, implant survival, and disease mortality were comparable in patients undergoing Type II internal hemipelvectomy alone compared to patients undergoing some combination of Type II/IV resection. However, compound resections increased the risk of neurological complications and experienced poorer MSTS functional scores.

Surgical Navigation and CAD-CAM-Designed PEEK Prosthesis for the Surgical Treatment of Facial Intraosseous Vascular Anomalies.

Background: Intraosseous vascular anomalies in the facial skeleton present significant diagnostic and therapeutic challenges due to complex anatomy. These anomalies represent about 0.5-1% of bony neoplastic and tumor-like lesions, usually presenting as a firm, painless mass. Most described intraosseous vascular malformations are venous malformations (VMs) and, more rarely, arteriovenous malformations. Objectives: The objectives of this work are to show our experience, protocol and the applications of computer planning, virtual surgery, CAD-CAM design, surgical navigation, and computer-assisted navigated piezoelectric surgery in the treatment of facial intraosseous vascular anomalies and to evaluate the advantages and disadvantages. Methods: Three females and one male with periorbital intraosseous vascular anomalies were treated using en-block resection and immediate reconstruction with a custom-made PEEK prosthesis. One lesion was in the supraorbital rim and orbital roof, one in the frontal bone and orbital roof, and two in the zygomatic region. We accomplished the resection and reconstruction of the lesion using virtual planning, CAD-CAM design, surgical navigation and piezoelectric device navigation. Results: There were no complications related to the surgery assisted with navigation. With an accuracy of less than 1 mm, the procedure may be carried out in accordance with the surgical plan. The surgeon's degree of uncertainty during deep osteotomies and in locations with low visibility was decreased by the use of the navigated piezoelectric device. Conclusions: Resection and reconstruction of facial intraosseous vascular anomalies benefit from this new surgical strategy using CAD-CAM technologies, computer-assisted navigated piezoelectric surgery, and surgical navigation.

A Revolutionary Device for Endovascular Aortic Repair of Abdominal Aortic Aneurysm: A Pilot Study

Background Endovascular repair for abdominal aortic aneurysms (AAA) has been the gold standard since it was established in 1991. Various graft configurations have been developed to overcome the limitations of endovascular aortic repair (EVAR), including contralateral gate cannulation (CGC). We propose a new device and technique intended to simplify endovascular AAA repair, along with reports of its application in six patients. Intervention The Taofan and Kang (T&amp;K) bidirectional endovascular aortic repair (B-EVAR (B-EVAR) device uses a main-body stent graft, two-limb extensions, and bare metal stent. The procedure involved accessing the right and left femoral arteries, followed by standard aortography evaluation using a pigtail catheter through the contralateral femoral access. The main body stent graft is deployed through ipsilateral femoral access using a balloon catheter, while the contralateral gate is cannulated with a hydrophilic coated wire. Both balloons were inflated simultaneously to ensure that the wires were in different lumens. Contralateral and ipsilateral extensions were deployed using a limb extension stent graft. Standard aortography evaluation was repeated. Result T&amp;K B-EVAR pilot procedures proved successful in various cases, from simple to complex anatomy, and even with varied graft stent deployment strategies. None of the patients had complications or prolonged length of stay (LOS). Follow-up CT did not reveal any high-pressure endoleaks. Conclusion T&amp;K B-EVAR has been proven to simplify endovascular AAA repair in six patients with excellent results. It is also reproducible, potentially universally applicable, and can offer operators ease of use, faster procedure times, reduced fluoroscopy times, and reduced contrast usage.

Study of Anatomical Variation of Intrahepatic Biliary Tree by Magnetic Resonance Cholangiopancreatography in Patients Attending Tertiary Hospital of Eastern Nepal

Background: There are several variations in the complex anatomy of intrahepatic bile ducts. Magnetic resonance cholangiopancreatographyis a safer imaging modality that effectively shows these variations, aiding in surgical planning and preventing iatrogenic injuries. This study aims to evaluate these anatomical variations using magnetic resonance cholangiopancreatography. Materials and Methods: This cross-sectional prospective study was performed in the Radiology Department of Nobel Medical College for one year using a convenient sampling technique. A total of 165 cases meeting the inclusion criteriawere selected and magnetic resonance cholangiopancreatography was performed to evaluate the anatomical variations. Results: The mean age of patients was 34.32±10.22 years out of which 51.5%were male and 48.5%were female. The branching pattern of right hepatic duct was typical in 66.7% of cases. The right posterior sectoral duct joining left hepatic duct was the most common variation seen in 15.2%. Right posterior sectoral duct joining the common bile duct was present in 6.7%. 6.1% of cases had unclassified variation whereas a trifurcation pattern was found in 5.5%. Left hepatic duct showed the typical branching pattern in 70.9% of cases. Segment II duct draining into the common trunk of segments III and IV was seen in 20%. Triconfluence among segments II, III, and IV was seen in 8.5% and 0.6% of cases had unclassified variation. Conclusion: This study revealed wide variation in branching patterns of intrahepatic biliary ducts. The typical branching pattern of right and left hepatic ducts were seen in majority of cases.

Comparison of cation and anion-mediated resolution enhancement of bioprinted hydrogels for membranous tissue fabrication.

Fabrication of engineered thin membranous tissues (TMTs) presents a significant challenge to researchers, as these structures are small in scale, but present complex anatomies containing multiple stratified cell layers. While numerous methodologies exist to fabricate such tissues, many are limited by poor mechanical properties, need for post-fabrication, or lack of cytocompatibility. Extrusion bioprinting can address these issues, but lacks the resolution necessary to generate biomimetic, microscale TMT structures. Therefore, our goal was to develop a strategy that enhances bioprinting resolution below its traditional limit of 150 μm and delivers a viable cell population. We have generated a system to effectively shrink printed gels via electrostatic interactions between anionic and cationic polymers. Base hydrogels are composed of gelatin methacrylate type A (cationic), or B (anionic) treated with anionic alginate, and cationic poly-L-lysine, respectively. Through a complex coacervation-like mechanism, the charges attract, causing compaction of the base GelMA network, leading to reduced sample dimensions. In this work, we evaluate the role of both base hydrogel and shrinking polymer charge on effective print resolution and cell viability. The alginate anion-mediated system demonstrated the ability to reach bioprinting resolutions of 70 μm, while maintaining a viable cell population. To our knowledge, this is the first study that has produced such significant enhancement in extrusion bioprinting capabilities, while also remaining cytocompatible.

Transcarotid artery revascularization outperforms transfemoral carotid artery stenting regardless of aortic arch type or degree of atherosclerosis

ObjectiveThe Centers for Medicare and Medicaid Services now approve reimbursement for transfemoral carotid artery stenting (TFCAS) in the treatment of standard-risk patients with carotid artery occlusive disease. TFCAS in patients with complex aortic arch anatomy is known to be challenging with worse outcomes. Transcarotid artery revascularization (TCAR) could be a preferable alternative in these patients owing to avoiding the aortic arch and using flow reversal during stent deployment. We aim to compare the outcomes of TCAR vs TFCAS across all aortic arch types and degrees of arch atherosclerosis. MethodsAll patients undergoing carotid artery stenting between September 2016 and October 2023 were identified in the Vascular Quality Initiative database. Patients were stratified into four groups: Group A (mild atherosclerosis and type I/II arch), Group B (mild atherosclerosis and type III arch), Group C (moderate/severe atherosclerosis and type I/II arch), and Group D (moderate/severe atherosclerosis and type III arch). The primary outcome was in-hospital composite stroke or death. Analysis of variance and χ2 tests analyzed differences for baseline characteristics. Logistic regression models were adjusted for potential confounders, and backward stepwise selection was implemented to identify significant variables for inclusion in the final models. Kaplan-Meier survival estimates, log rank test, and multivariable Cox regression models analyzed hazard ratios for 1-year mortality. ResultsA total of 20,114 patients were included (Group A: 12,980 [64.53%]; Group B: 1175 [5.84%]; Group C: 5124 [25.47%]; and Group D: 835 [4.15%]). TCAR was more commonly performed across the four groups (72.21%, 67.06%, 74.94%, and 69.22%; P < .001). Compared with patients with mild arch atherosclerosis, patients with advanced arch atherosclerosis in Group C and Group D were more likely to be female, hypertensive, smokers, and have chronic kidney disease. Patients with type III arch in Group B and Group D were more likely to present with stroke preoperatively. On multivariable analysis, TCAR had less than one-half the risk of stroke/death and 1-year mortality compared with TFCAS in the patients with the mildest atherosclerosis and simple arch anatomy (Group A) (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.31-0.61; P < .001; hazard ratio, 0.42; 95% CI, 0.32-0.57; P < .001). Group B patients with similar atherosclerosis but more complex arch anatomy had 70% lower odds of stroke/death with TCAR compared with TFCAS (OR, 0.30; 95% CI, 0.12-0.75; P = .01). Similar findings were also evident in patients with more severe atherosclerosis and simple arch anatomy (OR, 0.66; 95% CI, 0.44-0.97; P = .037). There was no significant difference in odds of stroke/death in patients with advanced arch atherosclerosis and complex arch (Group D) (OR, 0.91; 95% CI, 0.39-2.16; P = .834). ConclusionsTCAR is safer than TFCAS in patients with simple and advanced arch anatomy. This could be related to the efficiency of flow reversal vs distal embolic protection. The current Centers for Medicare and Medicaid Services decision will likely increase stroke and death outcomes of carotid stenting nationally if multidisciplinary approach and appropriate patient selection are not implemented.

Intravascular imaging-guided vs. angiography-guided percutaneous coronary intervention: A systematic review and meta-analysis of randomized controlled trials in high-risk patients and complex coronary anatomies

BackgroundDespite a large body of evidence supporting the use of intravascular imaging (IVI) to guide percutaneous coronary intervention (PCI), concerns exist about its universal recommendation. The selective use of IVI to guide PCI of complex lesions and patients is perceived as a rational approach. MethodsWe performed a systematic review and meta-analysis of randomized controlled trials (RCTs). Embase, PubMed, and Cochrane were systematically searched for RCTs that compared IVI-guided PCI with angiography-guided PCI in high-risk patients and complex coronary anatomies. The primary outcome was major adverse cardiac events (MACE). A random-effects model was used to calculate the risk ratios (RRs) with 95 % confidence intervals (CIs). ResultsA total of 15 RCTs with 14,109 patients were included and followed for a weighted mean duration of 15.8 months. IVI-guided PCI was associated with a decrease in the risk of MACE (RR: 0.65; 95 % CI: 0.56–0.77; p < 0.01), target vessel failure (TVF) (RR: 0.66; 95 % CI: 0.52–0.84; p < 0.01), all-cause mortality (RR: 0.71; 95 % CI: 0.55–0.91; p < 0.01), cardiovascular mortality (RR: 0.47; 95 % CI: 0.34–0.65; p < 0.01), stent thrombosis (RR: 0.55; 95 % CI: 0.38–0.79; p < 0.01), myocardial infarction (RR: 0.81; 95 % CI: 0.67–0.98; p = 0.03), and repeated revascularizations (RR: 0.70; 95 % CI: 0.58–0.85; p < 0.01) compared with angiography. There was no significant difference in procedure-related complications (RR: 1.03; 95 % CI: 0.75–1.42; p = 0.84) between groups. ConclusionsCompared with angiographic guidance alone, IVI-guided PCI of complex lesions and high-risk patients significantly reduced all-cause and cardiovascular mortality, MACE, TVF, stent thrombosis, myocardial infarction, and repeat revascularization.