Safety Issues in the Development of an Innovative Medical Parallel Robot Used in Renal Single-Incision Laparoscopic Surgery

Robotic-assisted single-incision laparoscopic surgery (SILS) is becoming an increasingly widespread field worldwide due to the benefits it brings to both the patient and the surgeon. The goal of this study is to develop a secure robotic solution for SILS, focusing specifically on urology, by identifying and addressing various safety concerns from an early design stage. Starting with the medical tasks and protocols, the technical specifications of the robotic system as well as potential; hazards have been identified. By employing competitive engineering design methods such as Analytic Hierarchy Process (AHP), Risk assessment, and Failure Mode and Effects Analysis (FMEA), a safe design solution is proposed. A set of experiments is conducted to validate the proposed concept, and the results strongly support the development of the experimental model. The Finite Element Analysis (FEA) method is applied to validate the mechanical architecture within a set of simulations, demonstrating the compliance of the robotic system with the proposed technical specifications and its capability to safely perform SILS procedures.

Artificial Intelligence-Based Hazard Detection in Robotic-Assisted Single-Incision Oncologic Surgery

THE PROBLEM

Single-incision surgery is a complex procedure in which any additional information automatically collected from the operating field can be of significance. While the use of robotic devices has greatly improved surgical outcomes, there are still many unresolved issues. One of the major surgical complications, with higher occurrence in cancer patients, is intraoperative hemorrhages, which if detected early, can be more efficiently controlled.

AIM

This paper proposes a hazard detection system which incorporates the advantages of both Artificial Intelligence (AI) and Augmented Reality (AR) agents, capable of identifying, in real-time, intraoperative bleedings, which are subsequently displayed on a Hololens 2 device.

METHODS

The authors explored the different techniques for real-time processing and determined, based on a critical analysis, that YOLOv5 is one of the most promising solutions. An innovative, real-time, bleeding detection system, developed using the YOLOv5 algorithm and the Hololens 2 device, was evaluated on different surgical procedures and tested in multiple configurations to obtain the optimal prediction time and accuracy.

RESULTS

The detection system was able to identify the bleeding occurrence in multiple surgical procedures with a high rate of accuracy. Once detected, the area of interest was marked with a bounding box and displayed on the Hololens 2 device. During the tests, the system was able to differentiate between bleeding occurrence and intraoperative irrigation; thus, reducing the risk of false-negative and false-positive results.

CONCLUSION

The current level of AI and AR technologies enables the development of real-time hazard detection systems as efficient assistance tools for surgeons, especially in high-risk interventions.

Integration of Virtual Reality in the Control System of an Innovative Medical Robot for Single-Incision Laparoscopic Surgery

In recent years, there has been an expansion in the development of simulators that use virtual reality (VR) as a learning tool. In surgery where robots are used, VR serves as a revolutionary technology to help medical doctors train in using these robotic systems and accumulate knowledge without risk. This article presents a study in which VR is used to create a simulator designed for robotically assisted single-uniport surgery. The control of the surgical robotic system is achieved using voice commands for laparoscopic camera positioning and via a user interface developed using the Visual Studio program that connects a wristband equipped with sensors attached to the user's hand for the manipulation of the active instruments. The software consists of the user interface and the VR application via the TCP/IP communication protocol. To study the evolution of the performance of this virtual system, 15 people were involved in the experimental evaluation of the VR simulator built for the robotic surgical system, having to complete a medically relevant task. The experimental data validated the initial solution, which will be further developed.

Risk Assessment-Oriented Design of a Needle Insertion Robotic System for Non-Resectable Liver Tumors

Medical robotics is a highly challenging and rewarding field of research, especially in the development of minimally invasive solutions for the treatment of the worldwide leading cause of death, cancer. The aim of the paper is to provide a design methodology for the development of a safe and efficient medical robotic system for the minimally invasive, percutaneous, targeted treatment of hepatocellular carcinoma, which can be extended with minimal modification for other types of abdominal cancers. Using as input a set of general medical requirements to comply with currently applicable standards, and a set of identified hazards and failure modes, specific methods, such as the Analytical Hierarchy Prioritization, Risk Analysis and fuzzy logic Failure Modes and Effect Analysis have been used within a stepwise approach to help in the development of a medical device targeting the insertion of multiple needles in brachytherapy procedures. The developed medical device, which is visually guided using CT scanning, has been tested for validation in a medical environment using a human-size ballistic gel liver, with promising results. These prove that the robotic system can be used for the proposed medical task, while the modular approach increases the chances of acceptance.

Integration of Real-Time Image Fusion in the Robotic-Assisted Treatment of Hepatocellular Carcinoma

Simple Summary

Hepatocellular carcinoma is one of the leading causes of cancer-related deaths worldwide. An image fusion system is developed for the robotic-assisted treatment of hepatocellular carcinoma, which is not only capable of imaging data interpretation and reconstruction, but also automatic tumor detection. The optimization and integration of the image fusion system within a novel robotic system has the potential to demonstrate the feasibility of the robotic-assisted targeted treatment of hepatocellular carcinoma by showing benefits such as precision, patients safety and procedure ergonomics.

Abstract

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related deaths worldwide, with its mortality rate correlated with the tumor staging; i.e., early detection and treatment are important factors for the survival rate of patients. This paper presents the development of a novel visualization and detection system for HCC, which is a composing module of a robotic system for the targeted treatment of HCC. The system has two modules, one for the tumor visualization that uses image fusion (IF) between computerized tomography (CT) obtained preoperatively and real-time ultrasound (US), and the second module for HCC automatic detection from CT images. Convolutional neural networks (CNN) are used for the tumor segmentation which were trained using 152 contrast-enhanced CT images. Probabilistic maps are shown as well as 3D representation of HCC within the liver tissue. The development of the visualization and detection system represents a milestone in testing the feasibility of a novel robotic system in the targeted treatment of HCC. Further optimizations are planned for the tumor visualization and detection system with the aim of introducing more relevant functions and increase its accuracy.

Association between PNPLA3[G]/I148M variant, steatosis and fibrosis stage in hepatitis C virus - genetic matters

There is an established correlation between the PNPLA3 rs738409 C > G single nucleotide polymorphism (SNP) and hepatic steatosis and fibrosis in hepatitis C virus (HCV) infected patients. However not all data is convergent regarding the exact impact of this SNP on the pattern of disease progression in different clinical settings. In this study, we aimed to further bridge the knowledge gap on this topic by investigating the role of the G allele in promoting steatosis, fibrosis and disease progression in relation to other metabolic and anthropometric host factors. Two hundred and fifty consecutive patients, previously diagnosed with chronic hepatitis C (CHC) underwent liver biopsy. Histology was assessed using the Metavir scoring system. Transient elastography was used for follow-up. Ninety-eight patients were genotyped for PNPLA3 rs738409 and followed up for fibrosis progression. PNPLA3 rs738409[G] allele was significantly correlated with severe steatosis (P = 0.04), severe fibrosis at the time of enrollment (P = 0.0005) and fibrosis progression with an OR of 10.31 (95% CI 1.06 - 99.59, P = 0.04), after a mean follow-up time of 62.85 (95%CI: 52.21 - 76.15) months. Severe steatosis at the time of enrollment had an OR of 11.02 (95% CI 1.48 - 82.09, P = 0.01) for the association with fibrosis progression. The HOMA-IR index was also positively correlated with severe fibrosis (P = 0.03) and fibrosis progression on univariate analysis (P = 0.02). PNPLA3 rs738409[G] allele is a reliable predictor for steatosis and fibrosis in CHC. The presence of G allele, along with severe steatosis and insulin resistance are significant predictors for fibrosis progression.

Increased lactate dehydrogenase activity is dispensable in squamous carcinoma cells of origin

Although numerous therapeutic strategies have attempted to target aerobic glycolysis to inhibit tumor progression, these approaches have not resulted in effective clinical outcomes. Murine squamous cell carcinoma (SCC) can be initiated by hair follicle stem cells (HFSCs). HFSCs utilize aerobic glycolysis, and the activity of lactate dehydrogenase (Ldh) is essential for HFSC activation. We sought to determine whether Ldh activity in SCC is critical for tumorigenesis or simply a marker of the cell type of origin. Genetic abrogation or induction of Ldh activity in HFSC-mediated tumorigenesis shows no effect on tumorigenesis as measured by number, time to formation, proliferation, volume, epithelial to mesenchymal transition, gene expression, or immune response. Ldha-null tumors show dramatically reduced levels of glycolytic metabolites by metabolomics, and significantly reduced glucose uptake by FDG-PET live animal imaging. These results suggest that squamous cancer cells of origin do not require increased glycolytic activity to generate cancers.

Most tumours are characterized by increased aerobic glycolytic activity. Here the authors show that elevated  aerobic glycolysis is not essential for cancer initiation by testing the effect of lactate dehydrogenase depletion on the ability of hair follicle stem cells (HFSCs) to form squamous cell carcinoma (SCC) in mouse genetic models.

Liver stiffness better predicts portal hypertension after HCV eradication

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Interferon-γ-inducible protein-10 in chronic hepatitis C: Correlations with insulin resistance, histological features & sustained virological response

BACKGROUND & OBJECTIVES

One of the multiple factors contributing to virological response in chronic hepatitis C (CHC) is interferon-gamma-inducible protein-10 (IP-10). Its level reflects the status of interferon-stimulated genes, which in turn is associated with virological response to antiviral therapy. The aim of this study was to evaluate the role of serum IP-10 levels on sustained virological response (SVR) and the association of this parameter with insulin resistance (IR) and liver histology.

METHODS

Two hundred and three consecutive biopsy proven CHC patients were included in the study. Serum levels of IP-10 were determined using ELISA method. IR was evaluated by homeostasis model assessment-IR (HOMA-IR). Histological features were assessed invasively by liver biopsy and noninvasively using FibroTest, ActiTest and SteatoTest. Predictive factors for SVR and their interrelations were assessed.

RESULTS

A cut-off value for IP-10 of 392 pg/ml was obtained to discriminate between responders and non-responders. SVR was obtained in 107 patients (52.70%). Area under the receiver operating characteristic curve for SVR was 0.875 with a sensitivity of 91.6 per cent, specificity 74.7 per cent, positive predictive value 80.3 per cent and negative predictive value 88.7 per cent. Higher values of IP-10 were associated with increasing stages of fibrosis (P<0.01) and higher grades of inflammation (P=0.02, P=0.07) assessed morphologically and noninvasively through FibroTest and ActiTest. Significant steatosis and IR were also associated with increased levels of IP-10 (P=0.01 and P=0.02). In multivariate analysis, IP-10 levels and fibrosis stages were independently associated with SVR.

INTERPRETATION & CONCLUSIONS

Our findings showed that the assessment of serum IP-10 level could be a predictive factor for SVR and it was associated with fibrosis, necroinflammatory activity, significant steatosis and IR in patients with chronic HCV infection.

[Environmental exposure chambers (EEC): A novel tool for pathophysiological and pharmaceutical research]

Airborne allergic diseases (allergic asthma, rhinitis and conjunctivitis) have reached epidemic proportions and are a great burden for both society and individuals. Therefore we need to better understand the physiopathological mechanisms and to increase clinical research in these diseases. However, traditional outpatient studies are difficult and have number of limitations, in particular the variability of allergen exposure. Yet allergen provocation tests, especially bronchial challenges in asthma, are excellent tools to measure the efficiency of anti-allergic therapies. Environmental exposure chambers (EEC) allow the performance of controlled allergen provocation tests on a large scale with remarkable sensitivity, specificity and reproducibility. Moreover, they allow a precise collection of allergic symptoms, making them interesting tools for patho-physiological and clinical studies. During the last thirty years, they have assisted the study of anti-allergic therapies and provided data on their pharmacodynamic characteristics, particularly in allergic rhinitis. However, there are still no EEC tests centered on asthma. The EEC of Strasbourg (ALYATEC^®) was developed to fulfill two objectives: to allow standardized allergenic and non-allergenic exposures with better control of the parameters than in other EEC and to offer a place to study asthma and anti-asthmatic therapies safely.

Prostate ultrasound: back in business!

The use of grey scale prostate ultrasound decreased after the implementation of magnetic resonance imaging (MRI) for the diagnosis and evaluation of prostate cancer. The new developments, such as multiparametric ultrasound and MRI-ultrasound fusion technology, renewed the interest for this imaging method in the assessment of prostate cancer. The purpose of this paper was to review the current role of prostate ultrasound in the setting of these new applications. A thorough reevaluation of the selection criteria of the patients is required to assess which patients would benefit from multiparametric ultrasound, who wouldbenefit from multiparametric MRI or the combination of both to assist prostate biopsy in order to ensure the balance between overdiagnosis and underdiagnosis of prostate cancer.

[Reconstruction of Defects after Oncologic Resection and Radiation - Indications for Microsurgical Reconstruction]

The surgical treatment of soft tissue sarcomas in the extremities frequently requires radiation therapy to achieve local tumour control. However, both adjuvant and neoadjuvant radiation are associated with significant morbidity caused by impaired wound healing, ulcers or osteonecrosis with subsequent fractures. This is due to altered local cell mediator levels, fibrosis occurring simultaneously with decreased cell division rates and diminished vascularity. This article describes a number of local conservative treatment options, all of which have limited success rates. In addition, it describes plastic surgical treatment options for radiation-induced local morbidity. Surgical reconstruction includes the full range of plastic reconstructive techniques. However, less complex options such as random pattern flaps or split thickness skin grafts are often associated with complications. Therefore, a large number of cases require free tissue transfer.

Non-invasive ménage à trois for the prediction of high-risk varices: stepwise algorithm using lok score, liver and spleen stiffness

BACKGROUND & AIMS

Liver stiffness (LS), spleen stiffness (SS) and serum markers have been proposed to non-invasively assess portal hypertension or oesophageal varices (EV) in cirrhotic patients. We aimed to evaluate the performance of a stepwise algorithm that combines Lok score with LS and SS for diagnosing high-risk EV (HREV) and to compare it with other already-validated non-invasive methods.

METHODS

We performed a cross-sectional study including 136 consecutive compensated cirrhotic patients with various aetiologies, divided into training (90) and validation (46) set. Endoscopy was performed within 6 months from inclusion for EV screening. Spleen diameter was assessed by ultrasonography. LS and SS were measured using Fibroscan. Lok score, platelet count/spleen diameter ratio, LSM-spleen diameter to platelet ratio score and oesophageal varices risk score (EVRS) were calculated and their diagnostic accuracy for HREV was assessed. The algorithm classified patients as having/not-having HREV. Its performance was tested and compared in both groups.

RESULTS

In the training set, all variables could select patients with HREV with moderate accuracy, the best being LSPS (AUROC = 0.818; 0.93 sensitivity; 0.63 specificity). EVRS, however, was the only independent predictor of HREV (OR = 1.521; P = 0.032). The algorithm correctly classified 69 (76.66%) patients in the training set (P < 0.0001) and 36 (78.26%) in the validation one. In the validation group, the algorithm performed slightly better than LSPS and EVRS, showing 100% sensitivity and negative predicted value.

CONCLUSION

The stepwise algorithm combining Lok score, LS and SS could be used to select patients at low risk of having HREV and who may benefit from more distanced endoscopic evaluation.

The metabolic syndrome is not correlated with the short-term risk of decompensation in patients with cirrhosis

BACKGROUND AND AIMS

Obesity proved to favor clinical decompensation in patients with cirrhosis. Our aim was to investigate if metabolic syndrome (MS) in cirrhotic patients represents a risk factor for decompensation.

METHODS

704 cirrhotics, included in a MS prevalence study were considered for evaluation; 121 patients were excluded because they did not complete the follow-up and 303 because they were decompensated at the start of the study. The remaining 280 were followed-up for a median period of 28.1+/-18 months. Patients were censored at the end of follow-up or at occurrence of a liver related event (LRE). Liver related events were considered the following: decompensation (ascites, variceal bleeding, hepatorenal syndrome, jaundice, encephalopathy), hepatocellular carcinoma, portal vein thrombosis and infections.

RESULTS

All MS criteria except the abdominal circumference were significantly different between decompensated and compensated patients. HDL-cholesterol levels were lower in decompensated patients. Among the 280 patients who completed the follow-up, 85 (30%) presented LREs. Ascites was the most frequent event. In the univariate analysis of the MS criteria we found a trend to significance of an inverse correlation between MS and LREs. There was no significant difference between patients with or without MS regarding survival free of LREs, 76.7% and 66.5%, respectively. None of the MS criteria reached the level of significance in discriminating patients with and without LREs.

CONCLUSIONS

In short term, presence of MS was not a risk factor for LREs. In short term, liver function and lower nutritional status influenced the prognosis. In decompensated patients, the MS defining criteria are not applicable.

Prospective non-invasive follow-up of liver fibrosis in patients with chronic hepatitis C

BACKGROUND

Non-invasive methods for the assessment of liver fibrosis are accurate in staging chronic liver diseases before treatment.

AIM

To prospectively assess liver fibrosis in chronic hepatitis C (CHC) in patients treated vs untreated, using non-invasive methods.

METHOD

224 patients with CHC were included in the study: 179 received antiviral treatment for 48 weeks, and 45 patients received no antiviral therapy. All patients underwent liver biopsy at baseline and were also evaluated by simple biological scores (APRI, HAPRI, Forns, Bonacini, Lok) and transient elastography (TE). The progression of fibrosis was non-invasively assessed over a period of 72 weeks.

RESULTS

Fibrosis decreased significantly in patients who gained sustained virological response (SVR). A significant decrease of fibrosis was also observed in all treated patients, irrespective of SVR when using APRI, HAPRI and Bonacini scores (p=0.001, 0.009 and 0.02). Untreated patients yielded constant values of fibrosis or a slight increase in follow-up. Patients with Lok score and stiffness predictive for cirrhosis had a decreasing trend of fibrosis (p=0.03 for Lok and 0.05 for TE), but persisting in the cirrhosis domain. Of the non responders, those who gained biological response demonstrated improvement of fibrosis assessed by APRI and TE.

CONCLUSION

The prospective follow-up of liver fibrosis assessed by simple biological scores and TE in patients with CHC revealed a downstaging of fibrosis in treated patients and especially in those who gained SVR.

Increased anticoagulant response to low-molecular-weight heparin in plasma from patients with advanced cirrhosis

INTRODUCTION

Cirrhotic patients may present thrombotic complications that warrant anticoagulant therapy. However, the efficacy of low-molecular-weight heparin (LMWH) in this clinical setting is still unclear.

AIMS/METHODS

To evaluate the in vitro effect of LMWH on thrombin generation (TG) in cirrhotic patients at different stages of liver disease. Thirty cirrhotics (10 Child Pugh A, 10 Child Pugh B and 10 Child Pugh C), 10 subjects with inherited type 1 antithrombin (AT) defect and 10 healthy controls were studied. TG was determined at baseline and with anti-Xa levels after the addition of enoxaparin at 0.35 and 0.7 U anti-Xa mL. The endogenous thrombin potential (ETP) ratio at 0.35 and 0.7 U anti-Xa mL was obtained by dividing ETP with LMWH by ETP at baseline.

RESULTS

Mean AT levels in all cirrhotic subgroups and in patients with AT deficiency were significantly lower than in controls. The 0.35 ETP ratio was significantly lower in cirrhotic patients than in controls (0.26 ± 0.1 vs. 0.48 ± 0.1, P < 0.001) and the reduction paralleled the severity of liver disease, in spite of the concomitant decrease in AT and anti-Xa activity. AT-deficient subjects showed a significantly increased 0.35 ETP ratio compared with both cirrhotic patients and controls (0.69 ± 1 vs. 0.26 ± 0.1, P < 0.001, and vs. 0.48 ± 0.1, P = 0.04 respectively). LMWH at 0.7 U anti-Xa mL completely inhibited TG in 9/30 cirrhosis patients with more advanced liver disease (Child Pugh B and C), whereas complete TG abolition was seen in only 1/10 controls.

CONCLUSIONS

Cirrhotic patients show an increased response to LMWH, which correlates with the severity of liver disease, in spite of reduced AT and anti-Xa activity levels. Thrombin generation may be a useful tool to monitor the response to LMWH in cirrhotic patients.

A novel pathophysiological-based panel of biomarkers for the diagnosis of nonalcoholic steatohepatitis

Non-invasive biochemical markers are useful to distinguish between nonalcoholic steatohepatitis (NASH) and simple steatosis. The aim of this study was to test the diagnostic value of a panel of biomarkers derived from the pathophysiological events involved in the development of NASH. A total of 79 patients: 20 not-NASH and 59 NASH were included in the study. Definitive NASH was defined according to Kleiner's classification. In all subjects, parameters of the metabolic syndrome, insulin resistance (HOMA-IR), adiponectin, interleukin-6 (IL-6) and total cytokeratin-18 (M65 antigen) were determined. Univariate and multivariate analysis were used to identify independent predictors of NASH. In multivariate analysis three markers were independently predictors of NASH: adiponectin, IL-6 and M65 levels. In decreasing order, the independent predictors of NASH (NAS≥5) were M65 with an AUROC of 0.791, IL-6 with an AUROC of 0.727 and adiponectin with an AUROC of 0.709. The combination of two biomarkers yelded an AUROC of 0.828 for M65 and IL-6, 0.841 for adiponectin and M65 and 0.852 for adiponectin and IL-6. The best value was obtained by triple combination: adiponectin, M65 and IL-6 with and AUROC of 0.903, Sp=85.7% (PPV=94.2%) and Se=84.5% (NPV=66.7%). In conclusion, a novel pathophysiological - based panel of biomarkers combining total CK-18, IL-6 and adiponectin may be useful to predict NASH.

Two or more synchronous combination of noninvasive tests to increase accuracy of liver fibrosis assessement in chronic hepatitis C; results from a cohort of 446 patients

BACKGROUND

The prediction of fibrosis is an essential part of the assessment and management of patients with chronic liver disease. Non-invasive tests (NITs) have a number of advantages over the traditional standard of fibrosis assessment by liver biopsy, including safety, cost-effectiveness, and widespread accessibility.

OBJECTIVES

The aim of this study was to determine the accuracy of certain biomarkers and transient elastography (TE) alone or in combination to predict the stage of liver fibrosis in chronic hepatitis C (CHC). Also, we examined whether the combination of certain biomarkers and TE could increase the diagnostic accuracy of liver fibrosis assessment.

PATIENTS AND METHOD

A total of 446 patients who were previously diagnosed with CHC were included in the study. In the study group, 6 blood-based scores (APRI, Forns, Fib-4, Hepascore, FibroTest, and Fibrometer) were calculated, and TE was performed to validate the stage of fibrosis, compared with liver biopsy (LB) as the standard.

RESULTS

Significant fibrosis (F ≥ 2) was predicted with an AUROC of 0.727, 0.680, 0.714, 0.778, 0.688, 0.797, and 0.751 for the APRI, Forns, Fib-4, FibroTest, Hepascore, and Fibrometer scores and TE (Fibroscan), respectively. Severe fibrosis (F ≥ 3) was predicted, with AUROCs ranging between 0.705 and 0.811 for Hepascore and Fibrometer, respectively. Of the biomarkers, Fibrometer had the highest AUROC value in predicting both significant and severe fibrosis. The combination of APRI or FIB-4 with Fibrometer increased the diagnostic accuracy for significant fibrosis (from 69.07 to 82.27 for APRI, P = 0.001 and from 57.74 to 81.33, P = 0.001 for Fib-4). Combining APRI or Fib-4 with TE also increased the diagnostic accuracy (from 69.07 to 80.70%, P = 0.001 for APRI and from 57.74 to 81.33%, P = 0.001 for Fib-4) for significant fibrosis. The association that included Fibrotest was also reliable for the improvement of diagnostic accuracy. These combinations were more accurate or the assessment of severe fibrosis.

CONCLUSIONS

The synchronous association between a simple, inexpensive score and a complex but expensive score or TE increases the diagnostic accuracy of non-invasive methods for the assessment of liver fibrosis stage.

Two or more synchronous combination of noninvasive tests to increase accuracy of liver fibrosis assessement in chronic hepatitis C; results from a cohort of 446 patients

BACKGROUND

The prediction of fibrosis is an essential part of the assessment and management of patients with chronic liver disease. Non-invasive tests (NITs) have a number of advantages over the traditional standard of fibrosis assessment by liver biopsy, including safety, cost-effectiveness, and widespread accessibility.

OBJECTIVES

The aim of this study was to determine the accuracy of certain biomarkers and transient elastography (TE) alone or in combination to predict the stage of liver fibrosis in chronic hepatitis C (CHC). Also, we examined whether the combination of certain biomarkers and TE could increase the diagnostic accuracy of liver fibrosis assessment.

PATIENTS AND METHOD

A total of 446 patients who were previously diagnosed with CHC were included in the study. In the study group, 6 blood-based scores (APRI, Forns, Fib-4, Hepascore, FibroTest, and Fibrometer) were calculated, and TE was performed to validate the stage of fibrosis, compared with liver biopsy (LB) as the standard.

RESULTS

Significant fibrosis (F ≥ 2) was predicted with an AUROC of 0.727, 0.680, 0.714, 0.778, 0.688, 0.797, and 0.751 for the APRI, Forns, Fib-4, FibroTest, Hepascore, and Fibrometer scores and TE (Fibroscan), respectively. Severe fibrosis (F ≥ 3) was predicted, with AUROCs ranging between 0.705 and 0.811 for Hepascore and Fibrometer, respectively. Of the biomarkers, Fibrometer had the highest AUROC value in predicting both significant and severe fibrosis. The combination of APRI or FIB-4 with Fibrometer increased the diagnostic accuracy for significant fibrosis (from 69.07 to 82.27 for APRI, P = 0.001 and from 57.74 to 81.33, P = 0.001 for Fib-4). Combining APRI or Fib-4 with TE also increased the diagnostic accuracy (from 69.07 to 80.70%, P = 0.001 for APRI and from 57.74 to 81.33%, P = 0.001 for Fib-4) for significant fibrosis. The association that included Fibrotest was also reliable for the improvement of diagnostic accuracy. These combinations were more accurate or the assessment of severe fibrosis.

CONCLUSIONS

The synchronous association between a simple, inexpensive score and a complex but expensive score or TE increases the diagnostic accuracy of non-invasive methods for the assessment of liver fibrosis stage.

PARASURG hybrid parallel robot for minimally invasive surgery

This paper presents the parallel hybrid robot, PARASURG 9M, for robotically assisted surgery, a robot which was entirely designed and produced in Romania. It is a versatile robot, being composed of a positioning and orientation module, PARASURG 5M with five degrees of freedom, having the possibility of attaching at its end either a laparoscope or an active surgical instrument for cutting/grasping, PARASIM, with four degrees of freedom. Based on its mathematical modelling, the first low-cost experimental model of the surgical robot has been built. The robot is part of the surgical robotic system, PARAMIS, with three arms, one used as a laparoscope holder, and other two for manipulating active instruments. When it is used as a manipulator of the camera, the user has the possibility to give commands in a large area for the positioning of the laparoscope using different interfaces: joystick, microphone, keyboard & mouse and haptic device. If the active surgical instrument, PARASIM, is attached, the robot commands are given through a haptic device. The main features that make the PARASURG 9M surgical robot suited for minimally invasive surgery are: precision, the elimination of the natural tremor of the surgeon, direct control over a smooth, precise, stable view of the internal surgical field for the surgeon. It also eliminates the need of a second surgeon to be present for the entire procedure (in the case of using the robot as a camera holder). In addition, there is improvement of surgeon dexterity in the case of using the PARASIM active instrument and better ergonomics in using the robot (in the case of the classic laparoscopy, the surgeon must adopt a difficult position for a long period of time, while the robot never gets tired). Having a relatively easy to understand, intuitive commanding system, the surgeons can rapidly adapt to the use of the PARASURG 9M robot in surgical procedures.

Homozygous F5 deep-intronic splicing mutation resulting in severe factor V deficiency and undetectable thrombin generation in platelet-rich plasma

BACKGROUND

Coagulation factor (F) V deficiency is associated with a bleeding tendency of variable severity, but phenotype determinants are largely unknown. Recently, we have shown that three patients with undetectable plasma FV and mild bleeding symptoms had sufficient residual platelet FV to support thrombin generation in platelet-rich plasma (PRP). Therefore, we hypothesized that FV-deficient patients with severe bleeding manifestations may lack platelet FV.

OBJECTIVES

To characterize a FV-deficient patient with a severe bleeding diathesis.

PATIENTS/METHODS

We performed FV mutation screening and functional studies in a 31-year-old male (FV:C < 1%) with umbilical bleeding at birth, recurrent hemarthrosis and muscle hematomas, and a recent intracranial hemorrhage.

RESULTS

The proband was homozygous for a deep-intronic mutation (F5 IVS8 +268A→G) causing the inclusion of a pseudo-exon with an in-frame stop codon in the mature F5 mRNA. Although platelet FV antigen was detectable by immunoprecipitation followed by Western blotting, no FV activity could be demonstrated in the proband's plasma or platelets with a prothrombinase-based assay. Moreover, no thrombin generation was observed in PRP triggered with 1-50 pm tissue factor (even in the presence of platelet agonists), whereas an acquired FV inhibitor was excluded. Clot formation in the proband's whole blood, as assessed by thromboelastometry, was markedly delayed but not abolished.

CONCLUSIONS

This is the first report of a pathogenic deep-intronic mutation in the F5 gene. Our findings indicate that the minimal FV requirement for viability is extremely low and suggest that thrombin generation in PRP may predict bleeding tendency in patients with undetectable plasma FV.

Interim analysis of the Stockholm III trial of preoperative radiotherapy regimens for rectal cancer

BACKGROUND

To address issues regarding the fractionation of radiotherapy (RT) and timing of surgery for rectal cancer, a multicentre trial has randomized patients to preoperative short-course RT with two different intervals to surgery, or long-course RT with delayed surgery. The present interim analysis assessed feasibility, compliance and complications after RT and surgery.

METHODS

Some 303 patients were randomized to either short-course RT (5 x 5 Gy) and surgery within 1 week (group 1), short-course RT and surgery after 4-8 weeks (group 2) or long-course RT (25 x 2 Gy) and surgery after 4-8 weeks (group 3).

RESULTS

Demographic data were similar between groups and there were few protocol violations (5.0-6 per cent). Eight patients (2.6 per cent) developed radiation-induced acute toxicity. There were no significant differences in postoperative complications between groups (46.6, 40.0 and 32 per cent in groups 1, 2 and 3 respectively; P = 0.164). Patients receiving short-course RT with surgery 11-17 days after the start of RT had the highest complication rate (24 of 37).

CONCLUSION

Compliance was acceptable and severe acute toxicity was low, irrespective of fractionation. Short-course RT with immediate surgery had a tendency towards more postoperative complications, but only if surgery was delayed beyond 10 days after the start of RT.

REGISTRATION NUMBER

NCT00904813 (http://www.clinicaltrials.gov).

Interim analysis of the Stockholm III trial of preoperative radiotherapy regimens for rectal cancer

BACKGROUND

To address issues regarding the fractionation of radiotherapy (RT) and timing of surgery for rectal cancer, a multicentre trial has randomized patients to preoperative short-course RT with two different intervals to surgery, or long-course RT with delayed surgery. The present interim analysis assessed feasibility, compliance and complications after RT and surgery.

METHODS

Some 303 patients were randomized to either short-course RT (5 x 5 Gy) and surgery within 1 week (group 1), short-course RT and surgery after 4-8 weeks (group 2) or long-course RT (25 x 2 Gy) and surgery after 4-8 weeks (group 3).

RESULTS

Demographic data were similar between groups and there were few protocol violations (5.0-6 per cent). Eight patients (2.6 per cent) developed radiation-induced acute toxicity. There were no significant differences in postoperative complications between groups (46.6, 40.0 and 32 per cent in groups 1, 2 and 3 respectively; P = 0.164). Patients receiving short-course RT with surgery 11-17 days after the start of RT had the highest complication rate (24 of 37).

CONCLUSION

Compliance was acceptable and severe acute toxicity was low, irrespective of fractionation. Short-course RT with immediate surgery had a tendency towards more postoperative complications, but only if surgery was delayed beyond 10 days after the start of RT.

REGISTRATION NUMBER

NCT00904813 (http://www.clinicaltrials.gov).

Performance of unidimensional transient elastography in staging non-alcoholic steatohepatitis

BACKGROUND/AIMS

Transient elastography (TE) is a noninvasive method for predicting liver fibrosis, mainly validated in patients with viral hepatitis. Information is still limited concerning its performance in non-alcoholic steatohepatitis (NASH) patients. We aimed to assess the value of TE in the prediction of fibrosis stage in NASH as well as the factors determining the discordance between the TE-predicted and the biopsy-proven fibrosis stage in these patients.

METHODS

Liver biopsy and TE were performed on 72 consecutive NASH patients. Fibrosis, lobular inflammation, ballooning and steatosis were evaluated (Brunt system).

RESULTS

Liver stiffness (LS) values ranged from 2.80 to 16.90 kPa. In the univariate analysis, LS was correlated with fibrosis (r=0.661; p<0.0001), steatosis (r=0.435, p<0.0001), ballooning (r=0.385; p=0.001) and lobular inflammation (r=0.364; p=0.002). In multivariate analysis, only fibrosis significantly correlated with LS (p<0.0001). The median (and range) LS values (kPa) according to the fibrosis stages were: 4.90 (2.80-7.30) for F0; 6.15 (4.80-12.50) for F1; 6.90 (3.30-16.90) for F2 and 14.00 (10.70-14.10) for F3, with significant difference between stages, except for F1-F2 (p=0.249). Cut off values were calculated for predicting each fibrosis stage: 5.3 kPa (AUROC=0.879) for F1; 6.8 kPa (AUROC=0.789) for F2; and 10.4 kPa (AUROC=0.978) for F3. Patients with false-positive results had a significantly higher ALT level than those with concordant results (p=0.039).

CONCLUSION

In NASH patients, TE allows a reliable assessment and prediction of liver fibrosis, especially in advanced stages. Steatosis, ballooning and inflammation do not influence liver stiffness.

Hepatitis C virus infection is a risk factor for gallstone disease: a prospective hospital-based study of patients with chronic viral C hepatitis

We evaluated the prevalence and the risk factors for gallstone disease in patients with chronic hepatitis C infection. We investigated 453 consecutively admitted patients with chronic infection with hepatitis C virus (HCV) (cirrhosis excluded) and 879 patients without liver disease (October 2006-April 2007). Gallstone disease was diagnosed if gallstones were present at ultrasonography or if there had been a previous cholecystectomy. Variables evaluated were age, gender, gallstone heredity, body mass index, waist circumference, parity, serum lipids, fatty liver, arterial hypertension, diabetes mellitus and metabolic syndrome (International Diabetes Federation criteria). Informed consent was obtained from all patients. We found that 88 of 453 (19%) patients with chronic HCV hepatitis (age 50.1 +/- 11.7 years) and 153 of 879 (17%) controls (age 60.6 +/- 12.6 years) had gallstone disease (GD). Abdominal obesity (OR = 2.108, 95% CI 1.287-3.452) and steatosis (OR = 3.699, 95% CI 2.277-6.008) were risk factors for GD in HCV patients. Gallstone heredity, dyslipidaemia, type 2 diabetes mellitus and metabolic syndrome increased the risk for GD in controls vs HCV patients. Our study shows that even HCV patients with chronic hepatitis but not cirrhosis have an increased prevalence of gallstones. Compared with controls, gallstones are present in HCV patients at a younger age and are associated with central obesity and liver steatosis, but not with gallstone heredity, dyslipidaemia, diabetes mellitus or metabolic syndrome. Although we could not establish a temporal relationship, the association between HCV infection and gall stone disease is real and appears to be causally linked, at least in predisposed individuals (obese and with liver steatosis).