Mechanical complications of cerebrospinal fluid shunt. Differences between adult and pediatric populations: myths or reality?

OBJECTIVE: Shunt malfunctions seem more frequent in children (44 to 81%) than in adults (18 to 29%). Because of discrepancies between studies, it is not possible to affirm this disparity. The objective was to verify whether the incidence of cerebrospinal fluid (CSF) shunt malfunctions is higher in children than adults. METHODS: We present a retrospective series of child and adult patients who underwent CSF shunt placement between 2000 and 2013 with a Sophysa SM8® valve. RESULTS: 599 adults and 98 children (sex ratio 1.28) underwent CSF shunt placement. Age at first surgery ranged between 1 day of life and 90 years (mean of 55.8 years, SD 25.8, median 64.8 years). The mean follow-up was 4 years (SD 4.264, 0-16; median 3 years). The cumulative complication rate was 25.5% (178/697). Mechanical complications were disconnection (25.1%), migration (11.8%), intracranial catheter obstruction (8.9%) and malposition (8.4%). The mean delay for the first revision was 1.90 years (0-13.9), (SD 2.73, median 0.5). The probability of shunt failure was 65% at 10 years in the child group and 36% at 10 years in the adult group. Moreover, in the child group, 33% of revisions occurred during the first year after shunt placement versus 17% in the adult group. Thus, the probability of shunt failure was higher in children than in adults (log-rank test, p < 0.001). CONCLUSIONS: This is the first retrospective study, comparing children and adults undergoing CSF shunt using the same valve, able to confirm the higher rate of complications in children.

Individual radiation exposure from computed tomography: a survey of paediatric practice in French university hospitals, 2010-2013.

OBJECTIVES: To describe computed tomography (CT) scanning parameters, volume CT dose index (CTDIvol) and dose-length product (DLP) in paediatric practice and compare them to current diagnostic reference levels (DRLs). METHODS: The survey was conducted in radiology departments of six major university hospitals in France in 2010-2013. Data collection was automatised to extract and standardise information on scanning parameters from DICOM-header files. CTDIvol and DLP were estimated based on Monte Carlo transport simulation and computational reference phantoms. RESULTS: CTDIvol and DLP were derived for 4,300 studies, four age groups and 18 protocols. CTDIvol was lower in younger patients for non-head scans, but did not vary with age for routine head scans. Ratios of 95th to 5th percentile CTDIvol values were 2-4 for most body parts, but 5-7 for abdominal examinations and 4-14 for mediastinum CT with contrast, depending on age. The 75th percentile CTDIvol values were below the national DRLs for chest (all ages) and head and abdominal scans (≥10 years). CONCLUSION: The results suggest the need for a better optimisation of scanning parameters for routine head scans and infrequent protocols with patient age, enhanced standardisation of practices across departments and revision of current DRLs for children. KEY POINTS: • CTDIvol varied little with age for routine head scans. • CTDIvol was lowest in youngest children for chest or abdominal scans. • Individual and inter-department variability warrant enhanced standardisation of practices. • Recent surveys support the need for revised diagnostic reference levels. • More attention should be given to specific protocols (sinuses, neck, spine, mediastinum).

High frequency percussive ventilation increases alveolar recruitment in early acute respiratory distress syndrome: an experimental, physiological and CT scan study.

BACKGROUND: High frequency percussive ventilation (HFPV) combines diffusive (high frequency mini-bursts) and convective ventilation patterns. Benefits include enhanced oxygenation and hemodynamics, and alveolar recruitment, while providing hypothetic lung-protective ventilation. No study has investigated HFPV-induced changes in lung aeration in patients with early acute respiratory distress syndrome (ARDS). METHODS: Eight patients with early non-focal ARDS were enrolled and five swine with early non-focal ARDS were studied in prospective computed tomography (CT) scan and animal studies, in a university-hospital tertiary ICU and an animal laboratory. Patients were optimized under conventional "open-lung" ventilation. Lung CT was performed using an end-expiratory hold (Conv) to assess lung morphology. HFPV was applied for 1 hour to all patients before new CT scans were performed with end-expiratory (HFPV EE) and end-inspiratory (HFPV EI) holds. Lung volumes were determined after software analysis. At specified time points, blood gases and hemodynamic data were collected. Recruitment was defined as a change in non-aerated lung volumes between Conv, HFPV EE and HFPV EI. The main objective was to verify whether HFPV increases alveolar recruitment without lung hyperinflation. Correlation between pleural, upper airways and HFPV-derived pressures was assessed in an ARDS swine-based model. RESULTS: One-hour HFPV significantly improved oxygenation and hemodynamics. Lung recruitment significantly rose by 12.0% (8.5-18.0%), P = 0.05 (Conv-HFPV EE) and 12.5% (9.3-16.8%), P = 0.003 (Conv-HFPV EI). Hyperinflation tended to increase by 2.0% (0.5-2.5%), P = 0.89 (Conv-HFPV EE) and 3.0% (2.5-4.0%), P = 0.27 (Conv-HFPV EI). HFPV hyperinflation correlated with hyperinflated and normally-aerated lung volumes at baseline: r = 0.79, P = 0.05 and r = 0.79, P = 0.05, respectively (Conv-HFPV EE); and only hyperinflated lung volumes at baseline: r = 0.88, P = 0.01 (Conv-HFPV EI). HFPV CT-determined tidal volumes reached 5.7 (1.1-8.1) mL.kg-1 of ideal body weight (IBW). Correlations between pleural and HFPV-monitored pressures were acceptable and end-inspiratory pleural pressures remained below 25cmH20. CONCLUSIONS: HFPV improves alveolar recruitment, gas exchanges and hemodynamics of patients with early non-focal ARDS without relevant hyperinflation. HFPV-derived pressures correlate with corresponding pleural or upper airways pressures. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02510105 . Registered on 1 June 2015. The trial was retrospectively registered.

Reossification of Bone Defects After Surgical Correction of Nonsyndromic Craniosynostosis: A Review and An Original Study.

BACKGROUND AND OBJECTIVES: Surgical correction of nonsyndromic craniosynostosis (NSC) aims to restore cranial shape. Reossification of bone defects is paramount for the best aesthetic prognosis. However, the literature on the quantitative evaluation of bone defects after NSC surgery is scarce. This study aimed to quantify and analyze the surface area of bone defects after NSC surgery and establish a threshold value for predicting persistent defects. METHODS: We conducted a systematic review and a prospective study of 28 children undergoing surgical treatment for NSC. We analyzed 426 defects on the first computed tomography scan (1 year postoperative) and 132 defects on the second computed tomography scan (4.6 years postoperative). Statistical analysis was performed using Spearman's rank correlation coefficient, Mann-Whitney-Wilcoxon rank-sum test, and Youden's J statistic. RESULTS: Our systematic review identified three studies reporting on bone defects' surface area and reossification rate. In our study, we found no statistically significant differences in the number or size of defects between sex or type of NSC. The threshold value for the surface area of bone defects above which there was a higher probability of persistent defects was 0.19 cm2 (Youden point), with an 89.47 % probability of persistence. Defects with a surface area below 0.19 cm2 had a considerably lower probability, only 15.07%, of persistence over time. CONCLUSION: Our study provides valuable quantitative data for managing bone defects after NSC surgery. Defects with a surface area above 0.19 cm2 should be monitored with radiological imaging because of the risk of persistence. Our findings highlight the importance of developing robust and reproducible methods for the quantitative analysis of bone defects after NSC surgery.

Metastatic melanoma treated by immunotherapy: discovering prognostic markers from radiomics analysis of pretreatment CT with feature selection and classification.

PURPOSE: Immunotherapy has dramatically improved the prognosis of patients with metastatic melanoma (MM). Yet, there is a lack of biomarkers to predict whether a patient will benefit from immunotherapy. Our aim was to create radiomics models on pretreatment computed tomography (CT) to predict overall survival (OS) and treatment response in patients with MM treated with anti-PD-1 immunotherapy. METHODS: We performed a monocentric retrospective analysis of 503 metastatic lesions in 71 patients with 46 radiomics features extracted following lesion segmentation. Predictive accuracies for OS < 1 year versus > 1 year and treatment response versus no response was compared for five feature selection methods (sequential forward selection, recursive, Boruta, relief, random forest) and four classifiers (support vector machine (SVM), random forest, K-nearest neighbor, logistic regression (LR)) used with or without SMOTE data augmentation. A fivefold cross-validation was performed at the patient level, with a tumour-based classification. RESULTS: The highest accuracy level for OS predictions was obtained with 3D lesions (0.91) without clinical data integration when combining Boruta feature selection and the LR classifier, The highest accuracy for treatment response prediction was obtained with 3D lesions (0.88) without clinical data integration when combining Boruta feature selection, the LR classifier and SMOTE data augmentation. The accuracy was significantly higher concerning OS prediction with 3D segmentation (0.91 vs 0.86) while clinical data integration led to improved accuracy notably in 2D lesions (0.76 vs 0.87) regarding treatment response prediction. Skewness was the only feature found to be an independent predictor of OS (HR (CI 95%) 1.34, p-value 0.001). CONCLUSION: This is the first study to investigate CT texture parameter selection and classification methods for predicting MM prognosis with treatment by immunotherapy. Combining pretreatment CT radiomics features from a single tumor with data selection and classifiers may accurately predict OS and treatment response in MM treated with anti-PD-1.

Mixed endometrioid and serous carcinoma developing in abdominal wall endometriosis following Cesarean section.

Abdominal wall endometriosis is unusual and mostly occurs in scars following Cesarean section. Although malignant transformation is rare, it must be recognized in order to benefit from radical resection. We report a very rare case of mixed endometrioid and serous carcinoma developing in a Cesarean section endometriosis scar and the way we managed it using surgery and chemotherapy. 18-FDG PET-CT imaging was performed to correctly stage the disease.

Anatomic variation: absence of portal vein bifurcation.

PURPOSE: To describe in CT scan the absence of a portal vein bifurcation. METHODS: We described the contrast-enhanced CT scan appearance of an absence of portal vein bifurcation in an "asymptomatic" 39 year old woman. RESULTS: It was a single intrahepatic portal vein which crossed the entire liver parenchyma from the right to the left and with a gradually decreasing diameter. The vascularization of the hepatic parenchyma was not ensured by third order branches, but directly made by second order ramifications which were regularly originated from the single IHPV along its course. This unusual portal vein mimicking a left portal vein agenesis, appeared in fact to be more in relation with a right portal vein agenesis. Distribution of hepatic veins and hepatic volume was normal. CONCLUSION: This very rare anatomic variation is easily detected on CT scan and appears important to describe for surgeon and interventional radiologists.

Massive hepatic necrosis with gastric, splenic, and pancreatic infarctions after ethanol ablation for hepatocellular carcinoma.

Hepatic necrosis after ethanol ablation for hepatocellular carcinoma (HCC), although rare, is well known and described, particularly in patients with chronic liver disease. The present report describes a rare case of massive hepatic necrosis with partial gastric, splenic, and pancreatic infarctions after local treatment of liver HCC with ethanol ablation and discusses the reasons for this complication. With the increasing use of percutaneous techniques to treat liver tumors, it is imperative for the interventional radiologist to be aware of the potential vascular complications of these techniques. An appreciation of vascular anatomy via multidetector computed tomography (CT) and/or magnetic resonance (MR) angiography is important when planning image-guided interventions.

Cardiac tamponade after malignant superior vena cava stenting: Two case reports and brief review of the literature.

Percutaneous stenting of the superior vena cava (SVC) is usually recommended as a palliative procedure for malignant SVC obstruction with low reported morbidity. Complications are uncommon and usually of minor consequence. We report two unusual cases of cardiac tamponade following SVC stenting in patients with malignant SVC syndrome. Echocardiography allows rapid diagnosis and guides pericardial drainage in the interventional radiology suite.

Epithelioid hemangioendothelioma of the liver with metastatic coeliac lymph nodes in an 11-year-old boy.

Epithelioid hemangioendothelioma of the liver is a very rare vascular tumour in children with intermediate malignant potential. We present a case in which the typical imaging appearances of coalescent peripheral hepatic masses with capsular retraction contributed to the diagnosis. A positron emission tomography-CT (PET-CT) procedure was performed in staging the disease with a strong suspicion of coeliac nodal involvement confirmed after laparotomy and histological analysis. Our case is unique because of the rarity of the disease, the young age of the child, and proven nodal metastases at initial diagnosis. The use of PET-CT allows better staging at initial diagnosis and thus better management with improved follow-up in these patients.

Quantification of steatosis in alcoholic and nonalcoholic fatty liver disease: Evaluation of four MR techniques versus biopsy.

PURPOSE: Given the growing prevalence of obesity and metabolic syndrome, the management of hepatic steatosis, especially its quantification, is a major issue. We assessed the quantification of liver steatosis using four different MR methods, in order to determine the one that is best correlated with the reference method which consists of histological measurement by liver biopsy. METHOD: Seventy-one successive patients requiring liver biopsy for acute or chronic liver disease were enrolled prospectively between March 2017 and March 2018, 11 were excluded and 60 were reported. Liver MR (1.5 T) was organised in order to be performed the same day, using four different steatosis quantification techniques (3-echo MRI, 6-echo MRI, 11-echo MRI and MR Spectroscopy). Quantitative histological and imaging data were compared. In a secondary analysis, we studied the possible influence of alcohol drinking, hepatic iron overload, and the presence of liver fibrosis. RESULTS: All four MR techniques were found to have excellent correlations with the histological measurements: 3-echo MRI (r = 0.852, p < 0.001), 6-echo MRI (r = 0.819, p < 0.001), 11-echo MRI (r = 0.818, p < 0.001) and MR Spectroscopy (r = 0,812, p < 0,001). Interestingly, we also found that the presence of alcohol consumption, iron overload and fibrosis did not interfere with measurements, whichever technique was used. CONCLUSION: In the evaluation of hepatic steatosis, our study showed very good correlations of all four MR techniques with the histological standard. There was no confounding factor in a representative group of patients with associated liver conditions such as alcohol consumption, fibrosis and iron overload, for each technique. All four MR techniques may be used in daily practice.

Personalised mechanical ventilation tailored to lung morphology versus low positive end-expiratory pressure for patients with acute respiratory distress syndrome in France (the LIVE study): a multicentre, single-blind, randomised controlled trial.

BACKGROUND: The effect of personalised mechanical ventilation on clinical outcomes in patients with acute respiratory distress syndrome (ARDS) remains uncertain and needs to be evaluated. We aimed to test whether a mechanical ventilation strategy that was personalised to individual patients' lung morphology would improve the survival of patients with ARDS when compared with standard of care. METHODS: We designed a multicentre, single-blind, stratified, parallel-group, randomised controlled trial enrolling patients with moderate-to-severe ARDS in 20 university or non-university intensive care units in France. Patients older than 18 years with early ARDS for less than 12 h were randomly assigned (1:1) to either the control group or the personalised group using a minimisation algorithm and stratified according to the study site, lung morphology, and duration of mechanical ventilation. Only the patients were masked to allocation. In the control group, patients received a tidal volume of 6 mL/kg per predicted bodyweight and positive end-expiratory pressure (PEEP) was selected according to a low PEEP and fraction of inspired oxygen table, and early prone position was encouraged. In the personalised group, the treatment approach was based on lung morphology; patients with focal ARDS received a tidal volume of 8 mL/kg, low PEEP, and prone position. Patients with non-focal ARDS received a tidal volume of 6 mL/kg, along with recruitment manoeuvres and high PEEP. The primary outcome was 90-day mortality as established by intention-to-treat analysis. This study is registered online with ClinicalTrials.gov, NCT02149589. FINDINGS: From June 12, 2014, to Feb 2, 2017, 420 patients were randomly assigned to treatment. 11 patients were excluded in the personalised group and nine patients were excluded in the control group; 196 patients in the personalised group and 204 in the control group were included in the analysis. In a multivariate analysis, there was no difference in 90-day mortality between the group treated with personalised ventilation and the control group in the intention-to-treat analysis (hazard ratio [HR] 1·01; 95% CI 0·61-1·66; p=0·98). However, misclassification of patients as having focal or non-focal ARDS by the investigators was observed in 85 (21%) of 400 patients. We found a significant interaction between misclassification and randomised group allocation with respect to the primary outcome (p<0·001). In the subgroup analysis, the 90-day mortality of the misclassified patients was higher in the personalised group (26 [65%] of 40 patients) than in the control group (18 [32%] of 57 patients; HR 2·8; 95% CI 1·5-5·1; p=0·012. INTERPRETATION: Personalisation of mechanical ventilation did not decrease mortality in patients with ARDS, possibly because of the misclassification of 21% of patients. A ventilator strategy misaligned with lung morphology substantially increases mortality. Whether improvement in ARDS phenotyping can decrease mortality should be assessed in a future clinical trial. FUNDING: French Ministry of Health (Programme Hospitalier de Recherche Clinique InterRégional 2013).

Dental contribution to paleo-odontological study of interarch relations in a human fossil.

In paleo-anthropology the fragility of fossil pieces (teeth and supporting bones) reduces their possible manipulation when studying the interarch relations. Two original impression methods of the jaw pieces are proposed, both adapted from those currently practiced in odontology. The plaster replicas of the dental occlusal parts are prepared according to the manufacturing procedures used in prosthetic dental laboratories. This study led to the following observations: 1) the impression techniques used by odontologists are adapted to the moulding of fragile samples. 2) The replicas elaborated from these mouldings made easier the cast manipulation in confrontation. 3) Macrophotography is a complement to direct observation of the pieces and their replicas. 4) For paleoanthropologic purposes, such studies can be easily carried out on almost any animal or human fossils.

Dental wear study in a 14th century skull of the Sao tribe, Cameroon.

The aim of this work was to study the wear affecting the almost complete dentition of a Sao individual fossil from Cameroon prehistory (XIVth century). Occlusal surfaces of the fossil fragile pieces were plaster replicated with an original technique adapted from usual dental impression methods (silicon elastomer polymerising by addition). Axial macro-photographs of both sectional dental casts and original pieces made it possible to produce drawings of the occlusal areas on transparencies in order to superimpose the lateral hemiarch counterparts in their optimal intercuspal position. The study of interarch contacts was completed by confronting and observing the occluding position of hemiarch replicas. The occlusal analysis revealed that the wear extent was equivalent on left and right molars. Hall's occlusal wear index and Van Reenen and Reinach's classification of proximal wear allow assessment of the degree of wear extent on premolar and molar sections in relation to the side or the arch observed. The even bilateral proximal and occlusal wears observed on the different kinds of homologous teeth appeared as the main contributor to this well-balanced interarch occlusion. The mandibular incisor losses and the particular type of wear affecting lower canines led to the conclusion of the presence of a labret, a great number of which was found in the area. According to Miles' method of age assessment based on tooth wear, the pieces studied belonged to an individual between 30 and 40 years old.

Human Foramen Magnum Area and Posterior Cranial Fossa Volume Growth in Relation to Cranial Base Synchondrosis Closure in the Course of Child Development.

BACKGROUND: To date, no study has compared the evolution of the foramen magnum area (FMA) and the posterior cranial fossa volume (PCFV) with the degree of cranial base synchondrosis ossification. OBJECTIVE: To illustrate these features in healthy children. METHODS: The FMA, the PCFV, and the ossification of 12 synchondroses according to the Madeline and Elster scale were retrospectively analyzed in 235 healthy children using millimeter slices on a computed tomography scan. RESULTS: The mean FMA of 6.49 cm in girls was significantly inferior to the FMA of 7.67 cm in boys (P < .001). In both sexes, the growth evolved in a 2-phase process, with a phase of rapid growth from birth to 3.75 years old (yo) followed by a phase of stabilization. In girls, the first phase was shorter (ending at 2.6 yo) than in boys (ending at 4.33 yo) and proceeded at a higher rate. PCFV was smaller in girls (P < .001) and displayed a biphasic pattern in the whole population, with a phase of rapid growth from birth to 3.58 yo followed by a phase of slow growth until 16 yo. In girls, the first phase was more active and shorter (ending at 2.67 yo) than in boys (ending at 4.5 yo). The posterior interoccipital synchondroses close first, followed by the anterior interoccipital and occipitomastoidal synchondroses, the lambdoid sutures simultaneously, then the petro-occipital and spheno-occipital synchondroses simultaneously. CONCLUSION: The data provide a chronology of synchondrosis closure. We showed that FMA and PCFV are constitutionally smaller in girls at birth (P ≤ .02) and suggest that a sex-related difference in the FMA is related to earlier closure of anterior interoccipital synchondroses in girls (P = .01). ABBREVIATIONS: AIOS, anterior interoccipital synchondrosesFMA, foramen magnum areaLS, lambdoid suturesOMS, occipitomastoidal synchondrosesPCFV, posterior cranial fossa volumePIOS, posterior interoccipital synchondrosesPOS, petro-occipital synchondrosesSOS, spheno-occipital synchondrosisyo, years old.

Dental arch relations analysed in a 14th century fossil skull of the Sao tribe, Cameroon.

Dental occlusal relations are rarely reported in paleo-anthropology. The manipulation of hemi-arch replicas, as well as the superimposition of drawings on calques traced from photographs, facilitated the description of the intra- and interarch relations. The occlusal interarch confrontation and the intermolar relation were observed and assessed in the horizontal, frontal and sagittal planes. Some measurements were helpful in the functional study. On the basis of knowledge in mandible kinematics a movement envelope of the first molar displacement during mastication was proposed. The dentition studied here was highly regular. It was a fine example of balanced wear for post-canine sectors. In spite of the lower canine extrusion, due to tribal mutilation of anterior teeth and to subsequent labret wearing, the interarch relations seemed not to have been altered.

[Post-traumatic secondary arteriovenous fistulae of the kidney and their embolization. Report of 3 cases]. / Fistules artério-veineuses secondaires post-traumatiques du rein et leur embolisation. A propos de 3 cas.

INTRODUCTION: Non-iatrogenic post-traumatic arteriovenous fistulas of the kidney raise a diagnostic and especially therapeutic problems. The authors report their experience based on 3 cases of arteriovenous fistulas treated by selective embolization during diagnostic arteriography. MATERIALS AND METHOD: In a series of 18 patients urgently admitted to hospital for kidney trauma during 2000, 3 patients presented a secondary arteriovenous fistula diagnosed on arteriography. All patients were initially treated by surveillance in the surgical ward. The diagnosis of arteriovenous fistula was subsequently suspected following recurrence of haematuria with a moderate fall in haemoglobin in two cases, and secondary appearance of lumbar pain without anaemia in the third case. For the two patients with secondary haematuria, arteriography demonstrated an arteriovenous fistula associated with an arterio-caliceal fistula. For the last patient, Doppler ultrasound suggested the diagnosis of arteriovenous fistula, which was confirmed by the arteriography. RESULTS: Selective embolization by "coils" and particle was performed during arteriography and ensured closure of the fistulas in every case. The postoperative course was uneventful for all three patients. With a mean follow-up of 7 months, no recurrence of the fistula has been observed. The remaining renal parenchyma is functional with preservation of renal function. CONCLUSION: The risk of arteriovenous fistula must be kept in mind in any case of lumbar trauma. Arteriography with selective embolization allows good control of these secondary fistulas while preserving a maximum of functional renal parenchyma, and therefore appears to be the treatment of choice of this complication.

Hepatic capsular retraction: spectrum of diagnosis at MRI.

Hepatic capsular retraction is an imaging feature that deserves the attention of the radiologist. Hepatic capsular retraction is associated with a number of hepatic lesions, benign or malignant, treated or untreated. The purpose of this pictorial review is to discuss the most common benign and malignant hepatic lesions associated with this feature with an emphasis on magnetic resonance imaging (MRI).