A Virtual Reality Environment to Visualize Three-Dimensional Patient-Specific Models by a Mobile Head-Mounted Display.

INTRODUCTION: With the availability of low-cost head-mounted displays (HMDs), virtual reality environments (VREs) are increasingly being used in medicine for teaching and clinical purposes. Our aim was to develop an interactive, user-friendly VRE for tridimensional visualization of patient-specific organs, establishing a workflow to transfer 3-dimensional (3D) models from imaging datasets to our immersive VRE. MATERIALS AND METHODS: This original VRE model was built using open-source software and a mobile HMD, Samsung Gear VR. For its validation, we enrolled 33 volunteers: morphologists (n = 11), trainee surgeons (n = 15), and expert surgeons (n = 7). They tried our VRE and then filled in an original 5-point Likert-type scale 6-item questionnaire, considering the following parameters: ease of use, anatomy comprehension compared with 2D radiological imaging, explanation of anatomical variations, explanation of surgical procedures, preoperative planning, and experience of gastrointestinal/neurological disorders. Results in the 3 groups were statistically compared using analysis of variance. RESULTS: Using cross-sectional medical imaging, the developed VRE allowed to visualize a 3D patient-specific abdominal scene in 1 hour. Overall, the 6 items were evaluated positively by all groups; only anatomy comprehension was statistically significant different among the 3 groups. CONCLUSIONS: Our approach, based on open-source software and mobile hardware, proved to be a valid and well-appreciated system to visualize 3D patient-specific models, paving the way for a potential new tool for teaching and preoperative planning.

Evolution of blood pressure in children with congenital and acquired solitary functioning kidney.

BACKGROUND: It is not yet clear if blood pressure and renal function changes evolve differently in children with a congenital or acquired solitary functioning kidney. This study aims to assess if there are any differences between these two types of solitary kidney patients. METHODS: Current research is a retrospective study assessing the evolution of glomerular filtration rate, proteinuria, and blood pressure in clinical records of 55 children with a solitary functioning kidney (37 congenital and 18 acquired). We used the medical records of children who had been assisted, in our unit of pediatric nephrology, for a period of 14 years (168 months), from the time of diagnosis, between January/1997 and December/2015. RESULTS: During the study period, glomerular filtration rate (T0 128.89 ± 32.24 vs T14 118.51 ± 34.45 ml/min/1.73 m2, p NS) and proteinuria (T0 85.14 ± 83.13 vs T14 159.03 ± 234.66 mg/m2/die, p NS) demonstrated no significant change. However, after 14 years of follow-up 76.4% of patients had increased levels of arterial hypertension with values over the 90th percentile for gender, age, and height. Specifically, children with an acquired solitary functioning kidney mainly developed hypertension [T0 2/17 (12%) vs T14 9/17 (52.9%) p < 0.025], whereas children with a congenital solitary functioning kidney mainly developed pre-hypertension [T0 3/38 (7.9%) vs T14 17/38 (44.7%) p < 0.0005]. CONCLUSIONS: The renal function of children with solitary functioning kidneys remains stable during a follow-up of 14 years. However, these children should be carefully monitored for their tendency to develop arterial blood pressure greater than the 90th percentile for gender, age, and height.

Routine clinical application of virtual reality in abdominal surgery.

BACKGROUND: The advantages of 3D reconstruction, immersive virtual reality (VR) and 3D printing in abdominal surgery have been enunciated for many years, but still today their application in routine clinical practice is almost nil. We investigate their feasibility, user appreciation and clinical impact. MATERIAL AND METHODS: Fifteen patients undergoing pancreatic, hepatic or renal surgery were studied realizing a 3D reconstruction of target anatomy. Then, an immersive VR environment was developed to import 3D models, and some details of the 3D scene were printed. All the phases of our workflow employed open-source software and low-cost hardware, easily implementable by other surgical services. A qualitative evaluation of the three approaches was performed by 20 surgeons, who filled in a specific questionnaire regarding a clinical case for each organ considered. RESULTS: Preoperative surgical planning and intraoperative guidance was feasible for all patients included in the study. The vast majority of surgeons interviewed scored their quality and usefulness as very good. CONCLUSIONS: Despite extra time, costs and efforts necessary to implement these systems, the benefits shown by the analysis of questionnaires recommend to invest more resources to train physicians to adopt these technologies routinely, even if further and larger studies are still mandatory.

Cardiorespiratory fitness: a comparison between children with renal transplantation and children with congenital solitary functioning kidney.

Children with end-stage renal disease are known to have a cardiorespiratory fitness significantly reduced. This is considered to be an independent index predictive of mortality mainly due to cardiovascular accidents. The effects of renal transplantation on cardiorespiratory fitness are incompletely known. We compared the maximal oxygen uptake (VO2 max) of children with a functioning renal transplant with that of children with congenital solitary functioning kidney, taking into consideration also the amount of weekly sport activity.

Impact of ambulatory blood pressure monitoring on the diagnosis of hypertension in children.

Screening of hypertension in children commonly starts with office measurement of the blood pressure according to the Fourth Report. The latter however does not account for masked hypertension (MH) on the one hand and white coat hypertension (WCH) on the other. We aimed to investigate in a single large pediatric population how much the addition of ambulatory blood pressure monitoring (ABPM) helps to refine the allocation to the different classes of blood pressure. In a retrospective study, we reclassified the records of a cohort of 500 children, who attended our department for investigation of possible hypertension, according to the Fourth Report and the revised ABPM interpretation scheme. As expected, ABPM interpretation scheme detected MH and WCH; however, 14% of children evaluated according to this scheme did not fit in any categories. On the other hand, applying the Fourth Report criteria, 80% of prehypertensive children ended up in the uncategorized or the MH groups. Our data confirm that ABPM detects the cases of MH and WCH, and minimizes the misplacement of prehypertensive children; unfortunately however, it also leaves a significant number of patients remain unclassified.

Variations of the blood gas levels and thermodilutional parameters during ICP monitoring after severe head trauma in children.

PURPOSE: The purpose of this study was to define, in children following head trauma and GSC ≤ 8, at which level of intracranial pressure (ICP), the thermodilutional, and gas analytic parameters implicated in secondary cerebral insults shows initial changes. METHODS: We enrolled in the study 56 patients: 30 males and 26 females, mean age 71 ± 52 months. In all children, volumetric hemodynamic and blood gas parameters were monitored following initial resuscitation and every 4 h thereafter or whenever a hemodynamic deterioration was suspected. During the cumulative hospital stay, a total of 1050 sets of measurements were done. All parameters were stratified in seven groups according to ICP (group A1 = 0-5 mmHg, group A2 = 6-10 mmHg, group A3 = 11-15 mmHg, group A4 16-20 mmHg, group A5 21-25 mmHg, group A6 26-30 mmHg, group A7 >31 mmHg). RESULTS: Mean values of jugular oxygen saturation (SJO2), jugular oxygen partial pressure (PJO2), extravascular lung water (EVLWi), pulmonary vascular permeability (PVPi), fluid overload (FO), and cerebral extraction of oxygen (CEO2) vary significantly from A3 (11-15 mmHg) to A4 (16-20 mmHg). They relate to ICP in a four-parameter sigmoidal function (4PS function with: r(2) = 0.90), inflection point of 15 mmHg of ICP, and a maximum curvature point on the left horizontal asymptote at 13 mmHg of ICP. CONCLUSIONS: Mean values of SJO2, PJO2, EVLWi, PVPi, FO, and CEO2 become pathologic at 15 mmHg of ICP; however, the curve turns steeper at 13 mmHg, possibly a warning level in children for the development of post head trauma secondary insult.

Noninvasive ventilation for acute respiratory distress in children with central nervous system disorders.

BACKGROUND: Acute respiratory distress (ARD) is a relatively frequent occurrence in patients suffering from central nervous system disorders (CNSD) and moderate to severe mental retardation. Whenever conventional therapy is little effective, noninvasive mechanical ventilation (NIV) is the additional treatment in patients with diseases of the peripheral nervous system. However, NIV is traditionally little employed in the acute phase in patients suffering from CNSD. In the latter, either conventional therapy is maintained or invasive mechanical ventilation is instituted if the patient's condition worsens severely. To challenge the traditional view, we conducted the study to prove that NIV is both applicable and effective in the treatment of ARD also in children with moderate to severe mental retardation. METHODS: We studied 44 children with ARD secondary to pneumonia and CNSD causing moderate to severe mental retardation. The children were divided in two groups. One group received conventional therapy and NIV, the other conventional therapy only, before being advanced to invasive ventilator support when nonresponding. On admission to hospital and one hour following admission we registered pH, PaCO(2), PaO2, A - a DO2 and the PaO2/FiO2 ratio. The mean hospital stay was also recorded. RESULTS: After one hour on NIV PaO2 and pH increased, PaCO(2) decreased, A - a DO2 and PaO2/FiO2 ratio improved. No changes in the above parameters were observed in children on conventional therapy only. Hospital stay was shorter when NIV was instituted. CONCLUSIONS: NIV is both applicable and beneficial in stabilizing blood gases, respiratory and cardiovascular parameters also in children with CNSD. Moreover its use shortens the hospital stay.

Influence of physical activity on cardiorespiratory fitness in children after renal transplantation.

BACKGROUND: Cardiorespiratory fitness is significantly reduced in children with end-stage renal disease. The role of renal transplantation in improving cardiorespiratory fitness has not been thoroughly investigated. METHODS: In this work, we wanted to assess whether, in children after a successful renal transplant, the amount of weekly physical exercise affects cardiorespiratory fitness and left ventricular mass (LVM). The study was conducted on 16 children after renal transplantation and 36 matching healthy controls. Four groups were formed according to the weekly amount of physical exercise; all children received an echocardiogram and underwent a treadmill exercise test according to the Bruce protocol. RESULTS: Cardiorespiratory fitness is worst in renal transplant children with a weekly physical exercise<3 h; renal transplant children with a physical exercise of 3-5 h per week attain a cardiorespiratory fitness comparable to controls with a sedentary lifestyle (<3-h exercise per week); healthy controls with a weekly physical exercise of 3-5 h per week show the highest levels of cardiorespiratory fitness; the LVM assessed via echocardiography follows the same pattern. CONCLUSIONS: In children with a successful renal transplant, a weekly physical exercise of 3-5 h significantly improves the cardiorespiratory fitness and the LVM, up to the level of matching healthy controls with a sedentary lifestyle (<3 h exercise per week).

Prognostic value of extravascular lung water index in critically ill children with acute respiratory failure.

PURPOSE: In critically ill adults, a reduction in the extravascular lung water index (EVLWi) decreases time on mechanical ventilation and improves survival. The purpose of this study is to assess the prognostic value of EVLWi in critically ill children with acute respiratory failure and investigate its relationships with PaO(2), PaO(2)/FiO(2) ratio, A-aDO(2), oxygenation index (OI), mean airway pressure, cardiac index, pulmonary permeability, and percent fluid overload. METHODS: Twenty-seven children admitted to PICU with acute respiratory failure received volumetric hemodynamic and blood gas monitoring following initial stabilization and every 4 h thereafter, until discharge from PICU or death. All patients are grouped in two categories: nonsurvivors and survivors. RESULTS: Children with a fatal outcome had higher values of EVLWi on admission to PICU, as well as higher A-aDO(2) and OI, and lower PaO(2) and PaO(2)/FIO(2) ratio. After 24 h EVLWi decreased significantly only in survivors. As a survival indicator, EVLWi has good sensitivity and good specificity. Changes in EVLWi, OI, and mean airway pressure had a time-dependent influence on survival that proved significant according to the Cox test. Survivors spent fewer hours on mechanical ventilation. We detected a correlation of EVLWi with percent fluid overload and pulmonary permeability. CONCLUSIONS: Like OI and mean airway pressure, EVLWi on admission to PICU is predictive of survival and of time needed on mechanical ventilation.

Might there be an association between polycystic kidney disease and noncompaction of the ventricular myocardium?

We report on a paediatric case of autosomal dominant polycystic kidney disease, where myocardial hypertrophy proved a consequence of noncompaction of the ventricular myocardium. Deletion of PKD1 and PKD2, the genes responsible for polycystic renal disease, has been linked also to disorganized myocardial arrangement in experimental animals. Two adults with polycystic kidney disease and myocardial hypertrophy in whom a careful diagnostic workup led to a diagnosis of non-compaction of the ventricular myocardium have been reported in the literature. Nephrologists must be aware of the possible association between the two diseases because early recognition of the disease may help in preventing the onset of complications.

Blood pressure load, proteinuria and renal function in pre-hypertensive children.

It is as yet unclear whether blood pressure load (BPL) can affect renal function in pre-hypertensive children. We have studied 250 children, with a mean age of 9.12 +/- 3.28 years, with the aim of assessing if pre-hypertension in children can indeed affect renal function. The study cohort consisted of 146 children with pre-hypertension (group P) and a control group of 104 children with normal blood pressure (group C). All children were tested for orthostatic proteinuria, an exclusion criterion, glomerular filtration rate (GFR), and proteinuria, and ambulatory blood pressure monitoring was performed. Based on the BPL, group P was further subdivided into group P1 (BPL 40%, high BPL). We found that GFR was reduced in pre-hypertensive children (90.74 +/- 48.69 vs. 110.32 +/- 20.30 ml/min per 1.73 m(2), p < 0.0001) and that proteinuria was increased (145.36 +/- 110.91 vs. 66.84 +/- 42.94 mg/m(2) per 24 h; p < 0.0001). However, mean values were still within normal limits. A comparison of the group with high BPL and that with low BPL revealed that the former had relatively reduced GFR (79.15 +/- 42.04 vs. 96.78 +/- 51.20 ml/min per 1.73 m(2); p < 0.006) and increased proteinuria (198.29 +/- 142.17 vs. 118.31 +/- 80.07 mg/m(2) per 24 h; p < 0.036). In comparison to the reference values of the normal population, the GFR was reduced and proteinuria was increased in the group with high BPL. Based on our results, pre-hypertension in children with high BPL seems to be associated with reduced GFR and increased proteinuria. A reasonable doubt remains that the patients with higher proteinuria and larger reduction of GFR may harbor an as yet unknown subclinical renal condition responsible for the onset of pre-hypertension. Therefore, children with even mildly elevated BP are at risk of developing renal damage and should change their lifestyle to prevent further increases in BP.

Hypotensive anesthesia with propofol and remifentanil: protective effect of alpha-tocopherol on renal function.

STUDY OBJECTIVE: To determine the effect of alpha-tocopherol in patients receiving hypotensive anesthesia with propofol-remifentanil. STUDY DESIGN: Prospective, randomized study. SETTING: University hospital. PATIENTS: 66 ASA physical status I and II patients, aged 32 to 56 years, scheduled for nasal polypectomy. INTERVENTIONS: Patients were allocated into two groups, the treatment and the control groups (T group and C group). T group received alpha-tocopherol 300 mg orally 5 to 6 hours before surgery. MEASUREMENTS: Sampling times and measurements were done before hypotension (t0), 45 minutes after starting hypotension (t1), 90 minutes after starting hypotension (t2), 45 minutes after recovery of normotension (t3), and 24 hours after surgery (t4). Renal function was assessed by testing glomerular and tubular functions: glomerular filtration rate, fractional excretion of sodium (FENA); fractional excretion of urea (FEUN); and urinary N-acetyl-1-beta-D-glucosoaminidase (NAG) index (NAGi). MAIN RESULTS: Glomerular filtration rate values remained unchanged in all patient populations. Fractional excretion of sodium was within reference ranges in both groups at times t0, t1, and t2. At time t3, a significant FE(NA) peak was observed. At this time, FENA was significantly higher in C group than T group (P < 0.001). FEUN time course was similar to the FENA trend. At time t4, FENA and FEUN returned to basal values. At time t3, NAGi was also increased without significant intergroup differences (P < 0.01, P < 0.001, and P < 0.01 vs times t0, t1, t2 in C group, respectively; P < 0.01, P < 0.01, and P < 0.001 vs times t0, t1, and t2 in T group, respectively). CONCLUSIONS: In patients without any renal disease, hypotensive anesthesia with propofol and remifentanil results in a transient tubular dysfunction, which appears to be minimized by the preoperative administration of alpha-tocopherol.

Relationship between global end-diastolic volume and cardiac output in critically ill infants and children.

OBJECTIVE: The objective of this study was to investigate possible correlations between the preload index global end-diastolic volume (GEDV) and the indexes of cardiac function, cardiac index, and stroke volume index in critically ill pediatric patients. The aim was to evaluate whether GEDV may help in the decision-making process concerning volume loading. DESIGN: Prospective clinical study. SETTING: Pediatric intensive care unit of the Bambino Gesù Children's Research Hospital. PATIENTS: Seventy patients, 40 male and 30 female, mean age 62 +/- 41 months (range 5-156 months), divided into six groups: group A, hemorrhagic shock, ten cases; group B, head injury, 21 cases; group C, septic shock, ten cases; group D, encephalitis, ten cases; group E, respiratory failure, nine cases; group F, cardiogenic shock, ten cases. INTERVENTIONS: All patients received volumetric hemodynamic monitoring following initial resuscitation and every 4 hrs thereafter or whenever a hemodynamic deterioration was suspected. During the cumulative in-hospital stay, a total 1,184 sets of measurements were done. MEASUREMENTS AND MAIN RESULTS: Findings are consistent with a statistically significant linear correlation of GEDV with cardiac index and stroke volume index in hemorrhagic shock (group A) (R2 = .647, p < .0001; R2 = .738, p < .0001) and cardiogenic shock (group F) (R2 = .645, p < .0001; R2 = .841, p < .0001). CONCLUSIONS: GEDV may potentially be a useful guide to treatment in preload-dependent conditions, such as hemorrhagic and cardiogenic shock. In the other groups where there is little relationship between preload and cardiac function indexes, the influence of non-preload-dependent mechanisms on cardiac output is certainly more significant.

Renal transplant in methylmalonic acidemia: could it be the best option? Report on a case at 10 years and review of the literature.

Methylmalonic acidemia (MMA) is an inborn error of organic acid metabolism. Patients with severe disease develop many complications despite treatment; often, the disease progresses to severe damage of the central nervous system or to end-stage renal disease (ESRD). When medical treatment is ineffective, liver, kidney, or combined liver and kidney transplantation is advocated. At present, there are no definite guidelines as for the organ to be transplanted, and results are inconsistent. We report on a 27-year-old woman with MMA MUT0. The clinical symptoms developed at age 4 months. She progressed to ESRD and received a kidney transplant in November 1996 at age 17 years. One hundred and twenty months after transplant, renal function is normal; although urinary levels of methylmalonic acid are above normal limits, no episodes of metabolic decompensation have been observed after transplantation. Although liver is the major site of methylmalonyl-CoA mutase activity, this case and similar ones in the literature suggest that the smaller mutase activity present in the transplanted kidney may be sufficient to ensure partial correction of the metabolism of organic acids sufficient to prevent the onset of episodes of metabolic decompensation. It is worth investigating whether kidney transplant can be a safer and more satisfactory alternative to liver transplantation in cases of MMA unresponsive to medical treatment although urine MMA excretion remains significantly elevated.

Renal and cardiovascular effects of angiotensin-converting enzyme inhibitor plus angiotensin II receptor antagonist therapy in children with proteinuria.

OBJECTIVE: We investigated whether the combination of an angiotensin-converting enzyme inhibitor and an angiotensin II type 1 receptor antagonist offers better control of proteinuria and cardiovascular parameters without causing adverse side effects. METHODS: We enrolled 10 children (mean age: 12.3 +/- 4.06 years) with proteinuria resulting from chronic renal diseases of various causes. The study consisted of 2 phases, 3 months each, for an overall 6-month observation time. During phase 1 (3 months), each child was assigned randomly to treatment with either an angiotensin-converting enzyme inhibitor or an angiotensin II type 1 receptor antagonist alone. During phase 2, each child was advanced to combination therapy with the addition of an angiotensin II type 1 receptor antagonist or an angiotensin-converting enzyme inhibitor, respectively. Renal function tests, echocardiography, and 24-hour ambulatory blood pressure monitoring were performed at the beginning of the study (time 0), at 3 months (time 1), and at 6 months (time 2). RESULTS: At time 2, proteinuria (change: -80.21 +/- 10.75%), interventricular septum index (change: -13.63 +/- 18.64%), posterior wall of the left ventricle index (change: -30.71 +/- 20.32%), and left ventricular mass index (change: -28.33 +/- 24.44%) were reduced significantly, compared with time 0 and time 1. No untoward side effects were detected during the study. CONCLUSIONS: In the short term, the combination of angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor antagonists for children with proteinuria of renal origin reduced proteinuria significantly, compared with baseline or either drug alone. Furthermore, echocardiographic studies gave evidence of reduction of left ventricular hypertrophy. Additional studies are needed to evaluate long-term results.