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Dialysis access-related distal ischaemia is a rare yet potentially rather risky complication of haemodialysis angioaccess. Timely diagnosis is crucial to target both the goals of the access team: first of all to preserve the function of the hand ideally along with angioaccess patency. Unfortunately for some patients, urgent access ligation and central vein catheter insertion would be needed to save the hand. After a first clinical examination to determine the diagnostic suspicion, the ultrasound evaluation would provide nearly all the needed information to confirm the diagnosis and to determine the most appropriate procedure to rescue the patient from distal ischaemia. In some cases, photoplethysmography would help in the differential diagnosis of other non-ischaemic causes of similar signs and symptoms. Angiography would complete the preoperative evaluation for some. Dialysis access-related distal ischaemia would be briefly reviewed, and a deep description of the ultrasound examination tools and findings would be provided for a tailored therapeutic approach.

Background: Arteriovenous fistula (AVF) is the preferred angioaccess for haemodialysis but suffers from a high stenosis rate, juxta-anastomotic stenosis (JAS) being the most frequent. Percutaneous transluminal angioplasty (PTA) of JAS would have some advantage (such as mini-invasive and vein sparing treatment), but higher recurrence rate is observed as compared to surgery. We report results of juxta anastomotic stenosis PTA using the ‘double guide technique’ (DGT) as described by Turmel-Rodrigues, in a selected cohort from our Vascular Access Centre. Patients and methods: From January to June 2018, 25 consecutive patients were treated by DGT. By means of retrograde access through the outflow vein by a 6 F introducer, two guide wires were navigated: one into proximal radial artery (GW1), the other into distal artery (GW2). GW2 was used to dilate juxta-anastomotic vein and anastomotic area with 6 mm high-pressure balloon, while by GW1 juxta-anastomotic artery was dilated with 4 mm semi-compliant balloon. Mean diameter of balloons were 6.7 and 4.1 mm for venous and arterial tract dilatation. Follow up was carried out up to 12 months. Prospectively collected data were analysed retrospectively. Results: One-year primary and secondary patency was 52% and 95% respectively. Recurrence rate was 0.56 procedure/pt/year. Mean access blood flow at 12 months was 830 ml/min. Conclusion: Double Guidewire Technique is an effective and minimally invasive procedure. By avoiding under dilation of JAS the recurrence rate resulted quite satisfactorily in our population.

Background and Aims Juxta-anastomotic stenosis is the most frequent complication of arteriovenous fistula (AVF) for haemodialysis (HD). Treatment options are surgical bypass by creating a more proximal anastomosis or endovascular treatment by angioplasty. The available literature data show equal outcomes in term of secondary patency, but a significantly higher rate of recurrent stenosis for endovascular treatment (0.5 procedure/AVF/year). We describe the results of endovascular treatment by “double guide technique” (DGT) as to Turmel Rodrigues original description, in a series of patients referred to our centre. Method We describe all consecutive patients treated by DGT in the first semester of 2018 because of a de novo occurring juxta-anastomotic stenosis of the arteriovenous fistula for haemodialysis. The procedure was carried out as described by Turmell Rodrigues. In short: by means of a single retrograde access through the outflow vein by a 6 french valved introducer, two guide wire are navigated into both proximal and distal artery. Two consecutive dilatation of the anastomosis area are then performed including first the juxta-anastomotic vein at 6 to 7 mm (mean 6.7mm, ds 0.55), followed by the juxta-anastomotic artery at 4mm (mean 4.1mm, ds 0.33), as show in figures. Follow up was carried out at 1, 3, 6 12 month by clinical examination and ultrasound examination. Prospectively collected data was analyzed retrospectively. Results 25 patients were treated during the first 6 month of 2018 by a single operator. Patients data (mean): age 71years, HD vintage 31month, AVF vintage 31month. AVF distribution were: distal radio-cephalic 32%, proximal radio-cephalic 52%, distal ulnar-basilic 8%, humero-basilic 8%. Mean preoperative AVF blood flow - as measured by duplex ultrasound (US) - was 540ml/min. 32% of AVF have preoperative blood flow >600ml/min but a critical stenosis ( Conclusion Endovascular treatment of juxta-anastomotic AVF stenosis by the DGT performed quite satisfactorily in our series and showed a low recurrence on the target lesion compared to data from literature. At 12 month the average AVF blood flow was below 1000ml/min. The technical advantage of the DGT consist in the single, small caliber percutaneous access, needed to complete the procedure. A larger series would confirm how this refinement of the technique compares with the improved results we preliminary observed.

Background: Arteriovenous fistula (AVF) for haemodialysis (HD) induces a volume/pressure overload which impairs bi-ventricular function and increases systolic pulmonary arterial pressure (PAPS) and left ventricular mass (LVM). In the presence of high blood flow (Qa) AVF (> 1.5 L/min/1.73 m2) and cardio-pulmonary recirculation (>20%), high-output congestive heart failure (CHF) may occur and AVF flow reduction is recommended. Proximal Radial Artery Ligation (PRAL) is an effective technique for distal radio-cephalic (RC) AVF flow reduction. Methods: we evaluated six HD and four transplant patients with high-flow RC AVF and symptoms of CHF who underwent PRAL. We compared echocardiographic (ECHO) findings before (T0) and 1 and 6 months (T1,T6) after PRAL. Preoperative ECHO was performed before (T0b) and after AVF anastomosis manual compression (T0c). Results: At T1 AVF flow reduction rate was 58.4% ± 13% and 80% of patients reported improved CHF symptoms. ECHO data showed an improvement of tricuspid annular plane systolic excursion (TAPSE) at T1 (p = 0.03) and a reduction of PAPS at T6 (p = 0.04). TAPSE improved after AVF anastomosis compression during preoperative ECHO (p = 0.03). Delta of TAPSE at the dynamic manoeuvre at T0 directly correlated with early (1 month after PRAL, p = 0.01) and late (6 months after PRAL, p = 0.04) deltas of TAPSE. Conclusions: AVF flow reduction after PRAL induces immediate regression of CHF symptoms, early improvement of TAPSE and late improvement of PAPS, suggesting a prevalent right sections involvement in CHF. Preoperative TAPSE modification after AVF anastomosis compression could represent a useful evaluation tool to determine which patients would benefit of PRAL.

Introduction Distal autogenous arteriovenous fistula (dAVF), considered the “gold standard” vascular access for haemodialysis, suffers from a high rate of impaired maturation. One of the usual causes is low-flow associated forearm arterial stenosis. In such cases, endovascular treatment by percutaneous transluminal angioplasty represents a helpful option to enable maturation of the vascular access. Currently, there are few reports concerning the treatment of this complication. Therefore, we describe our single-centre experience based on a retrospective review of prospectively collected data. Patients and methods We treated 18 consecutive patients from July 2007 to January 2014 (16 radio-cephalic, 2 ulno-basilic distal AVF). A low flow due to forearm artery stenosis was diagnosed by duplex examination, as routinely performed one month after dAVF creation. An anterograde trans-brachial access was used for a 4-mm high-pressure angioplasty of the stenosed artery. Results All interventions resulted in patent fistulas. Isolated percutaneous transluminal angioplasty (PTA) was required without need of stent placement. Mean blood flow increased from 304 mL/min, preoperatively, to 671 mL/min (pConclusions Endovascular approach is a helpful and minimally invasive procedure for treatment of delayed maturation of dAVF related to forearm artery stenosis.

Quality assessment in vascular access procedures for hemodialysis is not clearly defined. The aim of this article is to compare various guidelines regarding recommendation on quality control in angioaccess surgery. The overall population of end-stage renal disease patients and patients in need for hemodialysis treatment is growing every year. Chronic intermittent hemodialysis is still the main therapy. The formation of a functional angioaccess is the cornerstone in the management of those patients. Native (autologous) arteriovenous fistula is the best vascular access available. A relatively high percentage of primary failure and fistula abandonment increases the need for quality control in this field of surgery. There are very few recommendations of quality assessment on creation of a vascular access for hemodialysis in the searched guidelines. Some guidelines recommend the proportion of native arteriovenous fistula in incident and prevalent patients as well as the maximum tolerable percentage of central venous catheters and complications. According to some guidelines, surgeon’s experience and expertise have a considerable influence on outcomes. There are no specific recommendations regarding surgeon’s specialty, grade, level of skills, and experience. In conclusion, there is a weak recommendation in the guidelines on quality control in vascular access surgery. Quality assessment criteria should be defined in this field of surgery. According to these criteria, patients and nephrologists could choose the best vascular access center or surgeon. Centers with best results should be referral centers, and centers with poorer results should implement quality improvement programs.

Introduction: Outflow stenosis is a frequent complication of vascular access for hemodialysis. It may cause increased pressure within the angioaccess along with reduced blood flow. Elective treatment is percutaneous transluminal angioplasty; however, when a long occlusion (>2 cm) occurs, success and mid-term patency of endovascular treatment are uncertain. We describe a case series of patients with long occlusion of elbow outflow complicating an otherwise excellent forearm arteriovenous fistula, treated by a bypass across the elbow through cubital vein transposition. Patients and methods: Six consecutive patients have been treated between 2015 and 2017; all were referred because of either low flow, increased venous pressure, excessive bleeding time, or recirculation and were examined by duplex ultrasound. A total of 83% of patients showed associated thrombosis within the access. All procedures were performed under loco-regional anesthesia and preventive hemostasis. Surgical thrombectomy was also performed when needed. Results: Immediate success was obtained in all but two patients converted in veno-venous polytetrafluoroethylene bypass. Post-operative blood flow increased from 316 to 878 mL/min. All patients were dialyzed through the forearm access immediately the day after surgery, without the need for central vein catheter. Overall, 75% of patients needed a percutaneous transluminal angioplasty of the veno-venous anastomosis within 6 months. Primary and secondary patency at 12 and 24 months were 25%–0% and 100%–100%, respectively. Conclusion: Outflow reconstruction through the elbow bypass by cubital vein transposition is a valuable resource to rescue radiocephalic arteriovenous fistula complicated by outflow obstruction, avoiding the use of an interim central vein catheter. Endovascular treatment is vital to maintain functional patency in the mid- and long term.

Metformin (MF) accumulation during acute kidney injury is associated with high anion gap lactic acidosis type B (MF-associated lactic acidosis, MALA), a serious medical condition leading to high mortality. Despite dose adjustment for renal failure, diabetic patients with chronic kidney disease (CKD) stage III–IV are at risk for rapid decline in renal function by whatever reason, so that MF toxicity might arise if the drug is not timely withdrawn. Sixteen consecutive patients were admitted to our Hospital’s Emergency Department with clinical findings consistent with MALA. Fifteen had prior history of CKD, 60 % of them with GFR between 30 and 60 ml/min. Of these, 5 required mechanical ventilation and cardiovascular support; 3 promptly recovered renal function after rehydration, whereas 10 (62 %) required continuous veno-venous renal replacement treatment. SOFA and SAPS II scores were significantly related to the degree of lactic acidosis. In addition, lactate levels were relevant to therapeutic choices, since they were higher in dialyzed patients than in those on conservative treatment (11.92 mmol/l vs 5.7 mmol/l, p = 0.03). The overall death rate has been 31 %, with poorer prognosis for worse acidemia, as serum pH was significantly lower in non-survivors (pH 6.96 vs 7.16, p > 0.04). Our own data and a review of the literature suggest that aged, hemodynamically frail patients, with several comorbidities and CKD, are at greater risk of MALA, despite MF dosage adjustment. Moreover, renal replacement therapy rather than simple acidosis correction by administration of alkali seems the treatment of choice, based on eventual renal recovery and overall outcome.

Purpose Guidelines recommend autogenous radial-cephalic AV fistula (RCAVF) as the first choice for hemodialysis. Concern has been raised that this is not suitable in the elderly. We assessed the results of microsurgery for RCAVF creation comparatively in patients older and younger than 70 years. Methods We prospectively followed 126 patients for three years. After systematic clinical and ultrasound assessment, a RCAVF was created using a surgical microscope. Patency was assessed immediately, at one week, one month and one year. Outcomes were recorded and stratified into two groups: 70y. Results RCAVF was created in 75.4% and 70.8% of the 70y groups, respectively. Incidence of early failure was 11% (70y). Primary and secondary patency at one year was 67% and 84% (70y). Conclusions Microsurgery enabled the creation of RCAVF in >70y with acceptable risk of failure and slight differences by comparison with

The aim of the multidisciplinary team committed to the care of vascular access (VA) for hemodialysis is to prolong as much as possible the functional patency of the access. Stenosis is definitely the most frequent complication of arteriovenous VA. Whereas the best surveillance strategy is still a matter of debate, some evidence is now available about treatment indication and options. The available body of evidence on the best strategy facing this complication of VA is reviewed.

Distal radio-cephalic arteriovenous fistula is the 'gold standard' vascular access for chronic hemodialysis. Its main drawback is early failure, which can complicate up to 50 % of this surgical procedure. Two scenarios of failure are possible: early post-operative thrombosis or impaired maturation. The first is mainly due to a defective preoperative evaluation or poor surgical procedure. The latter is a patent angioaccess unable to deliver adequately hemodialysis due to a persistently low blood flow or difficult cannulation. In this article, the causes of impaired maturation will be reviewed, ranging from the stenosis causing low flow to the deep location of the vein in the obese. Treatment options will be described in thorough technical detail, in order to allow the angioaccess team to master them in daily practice.

Background and objectives: Transplantation should favorably affect coronary calcification (CAC) progression in dialysis; however, changes in CAC score in the individual patient are not reliably evaluated. Design, setting, participants & measurements: The authors used special tables of reproducibility limits for each score level to study, by multislice computed tomography and biochemistries, the 2-year changes in CAC in 41 transplant patients (age 48 ± 13 yr, 25 men, dialysis vintage 4.8 ± 4.3 yr, underwent transplant 6.2 ± 5.5 yr prior). Thirty balanced dialysis patients served as controls. Results: In the study group, Agatston score was stable, and C-reactive protein decreased, whereas fetuin and osteoprotegerin increased. In the control group, Agatston score increased, parathyroid hormone and phosphate decreased, and inflammation markers were persistently twice as high as in the study group. With regard to individual changes, 12.2% transplant patients worsened, compared with 56.6% of patients in dialysis (P < 0.0001). Patients without calcification at entry showed slower progression in transplantation (8.3%) than in dialysis (44.4%; P < 0.034), and the difference was similar to that observed in cases with CAC (17.6% versus 61.9%; P < 0.007). Discriminant analysis indicated parathyroid hormone, the modality of therapy (dialysis or transplantation), and erythrocyte sedimentation rate as the variables most associated with worsening. Conclusions: Renal transplantation lowers but does not halt CAC progression. Inflammation and hyperparathyroidism are associated with progression in the populations studied.

Background: As far as paediatric traumatic brain injury is concerned, it is difficult to quantify the extent of the primary insult, to monitor secondary changes and to predict neurological outcomes by means of the currently used diagnostic tools: physical examination, Glasgow Coma Scale (GCS) score and computed tomography. For this reason, several papers focused on the use of biochemical markers (S100B, neuron-specific enolase) to detect and define the severity of brain damage and predict outcome after traumatic head injury or cardiac arrest. Objective: The aim of this paper is measuring the range of S100B serum concentrations in children affected by traumatic brain injury and describing the possible roles of this protein in the reaction to trauma. Methods: Fifteen children aged 1–15 years were included in the study. Traumatic brain injury severity was defined by paediatric GCS score as mild (9 patients), moderate (2 patients) or severe (4 patients). Blood samples for S100B serum measurement were taken at emergency department admission and after 48 h. Results: The serum S100B concentration was higher in the group of severe trauma patients, who scored the lowest on the GCS at admission, and among them, the highest values were reported by the children with concomitant peripheral lesions. Conclusions: The role of S100B in paediatric traumatic brain injury has not been clarified yet, and the interpretation of its increase when the head trauma is associated with other injuries needs the understanding of the physiopathological mechanisms that rule its release in the systemic circulation. The levels of S100B in serum after a brain injury could be related to the mechanical discharge from a destroyed blood-brain barrier, or they could be due to the active expression by the brain, as a part of its involvement in the systemic inflammatory reaction. Early increase of this protein is not a reliable prognostic index of neurological outcome after pediatric traumatic brain injury, since even very elevated values are compatible with a complete neurological recovery.

Copyright © 2015 The Korean Society of Radiology Giant Hepatic Artery Aneurysm Associated with Immunoglobulin G4-Related Disease Successfully Treated Using a Liquid Embolic Agent Michele Rossi, MD, Edoardo Virgilio, MD, Florindo Laurino, MD, Gianluigi Orgera, MD, Paolo Mene, MD, Nicola Pirozzi, MD, Vincenzo Ziparo, MD, Marco Cavallini, MD Department of Interventional Radiology, Medical and Surgical Sciences and Translational Medicine, and Department of Nephrology, Faculty of Medicine and Psychology “Sapienza”, St. Andrea Hospital, Rome 00189, Italy

Purpose The purpose of this study is to report surgical techniques to facilitate cannulation of deep matured veins. Methods and Results 1) Basilic vein tunnel superficialization with rerouting in an anterior tunnel is mandatory for brachial-basilic arteriovenous fistula (AVF), mostly performed in a second surgical stage. The elevation technique, which could necessitate cannulation of the vein through the overlying scar, is not advisable. 2) Femoral vein superficialization is a one-stage surgical operation. Complications of this high-flow AVF are distal ischemia (diabetes and occlusive arterial disease are contraindications), iliac vein stenosis due to intimal hypertrophy and cardiac issues. Nevertheless, we have achieved high long-term patency rates (N = 70). Primary patency rates at 1 and 9 years were 91% ± 4% and 45% ± 11%, respectively. Secondary patency rates at 1 and 9 years were 84% ± 5% and 56% ± 9%, respectively. 3) Lipectomy for superficialization of the forearm radial-cephalic AVF is described for obese patients. Subcutaneous tissues are resected using two transverse incisions. Mobilization of the vein is avoided. At 3 years (N = 49), we recorded 63% ± 8% and 88% ± 7% primary and secondary patency rates, respectively. Anterior transposition of the forearm basilic vein is not necessary when using microsurgery for creation of distal ulno-basilic AVF. 4) VWING is a novel surgically implanted device to help buttonhole technique cannulation. It is too early to draw any conclusion from the preliminary published reports. Conclusions Tunnel-transposition and lipectomy are efficient techniques to allow easy needling of deeply situated upper-arm basilic vein, and cephalic vein in obese patients, respectively.

Purpose To demonstrate that treatment with distal radial artery ligation (DRAL), based on preoperative evaluation with duplex ultrasound, is effective for correction of hand ischemia related to distal radiocephalic arteriovenous fistula (AVF). Methods Two patients with symptoms of hemodialysis access-induced distal ischemia (HAIDI) related to radiocephalic AVF at wrist (necrotic lesion of fingers, pain at rest and loss of sensory function) were studied with preoperative duplex examination. Color Doppler ultrasound (CDU) showed low-normal flux (700 and 500 mL/min respectively), retrograde flow in the DRA and increased digital perfusion after manual occlusion of DRA. They were both treated by ligation of the DRA. Results Both patients had immediate improvement of ischemic symptoms. Reversed DRA flow disappeared and peripheral flow ameliorated. Postoperative AVF flow was 500 and 350 mL/min, stable at 16 and 8 months of follow-up, respectively. Conclusions Preoperative CDU examination, simulating reversed DRA flow interruption, seems to be an effective tool to predict the success of DRAL procedure.

Forearm arteriovenous fistula (AVF) is a direct anastomosis between the radial artery and the cephalic vein or the ulnar artery and the basilic vein, which are small-caliber vessels. The surgical technique must be precise to avoid postoperative stenosis of the anastomosis which may result in early thrombosis or nonmaturation. In our experience, microsurgery and preventive hemostasis are two major contributions to creation of forearm AVF. Using these techniques, construction of a radial-cephalic fistula was possible in 78% of children in our hospital, with 60% secondary patency rates at 4 years. In a personal unpublished series, 69% of the first arteriovenous angioaccess of adult patients were forearm fistulae, with 63% and 91% primary and secondary 1-year patency rates, respectively. Finally, 68% primary patency and 96% secondary patency rates at 1 year were reported by Pirozzi et al. in adults with an internal diameter of

Surgical reinterventions for treatment of complications or ligation of haemodialysis vascular access (VA), when performed in or below the mid/lower part of the upper arm, could benefit from the use of preventive haemostasis with an inflatable tourniquet. This technique offers several advantages, such as the reduced risk of bleeding and the increased accuracy of dissection allowing for a minimally invasive approach. The use of preventive haemostasis is safe, economical and time-saving. All the secondary procedures on VA that could benefit from its use are reviewed.

Loco-regional anesthesia, along with the neurosensitive inhibition causes arterial and venous vasodilatation, that could be of interest for vascular access surgery. We evaluated the long term vasoplegia persistence after brachial plexic block.Five patients submitted to brachial plexus block for an orthopedic procedure have been observed. Both radial arteries, that of the blocked arm and the opposite as a control, were analyzed by ultrasound examination, at time 0 and 360 minutes after anesthesia induction. All patients were treated with the same anesthesiologic protocol: axillary approach, use of an electroneurostimulator, injection 10 ml of ropivacain 7.5% + 10 ml of mepivacain 2%. The parameters evaluated from the arterial ultrasound flowmetry were: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI).No modification of the arterial flow were observed in the control arm at 0 and 360'after block induction. The blocked arm instead showed a significant decrease of the resistive index, stable at 360 minutes.The vasoplegia accompaning plexic block lasted 6 hours after anesthesia induction. Whereas this longstanding haemodynamic effect is beneficial for early patency of vascular access for hemodialysis, needs to be ascertained by further investigations.

We found very interesting the manuscript written by Dr. Steinau et al. [1] recently published in your journal. The author proposed their approach for the management of abdominal compartment syndrome (ACS) in childhood presenting a wide case mix of pathology ranging from neonates to school children. We agree that the gold standard for the indirect intrabdominal preassure (IAP) measurement both in adults and children is the intra-bladder pressure monitoring with an intermittent saline bolus. In accordance with the adult guidelines, intrabdominal hypertension (IAH) in children is firstly managed with a conservative therapy, while in the presence of ACS (low abdominal perfusion pressure associated to a new onset of organ dysfunction) early abdominal decompression remains a mandatory approach in order to reduce the high mortality rate associated with this condition [2, 3]. Unfortunately, the ‘‘numbers’’ used in the adult population to perform an abdominal decompression are not applicable in children since the variable abdomen compliance especially in neonates and infants [2]. Many authors [1, 2, 4] suggested proper cut-off values for IAH, to establish the ‘‘critical pressure number’’ at which regularly a switch from IAH to ACS in pediatric patients can be observed. In his work, Dr. Steinau et al. used the criteria proposed by Dr. Eijke [4] to define the pediatric ACS [3]. He considered the pediatric ACS as a lasting IAH higher than 12 mmHg combined with at least one organ dysfunction. We believe that a fixed ‘‘critical’’ number is not suitable for all pediatric patients and that the values proposed by Dr. Stainau are just indicative of an evolving process that could lead or not to a multiple organ dysfunction. Both in adults and children, clinical examination and laboratory testing (base deficit, lactate, unpaired dieresis) are sensitive in detecting abnormalities of tissue perfusion during ACS only after sustained periods of inadequate perfusion, furthermore the early changes in organ metabolism are not easily identified with the traditional monitoring systems. We believe that the outcome of ACS would improve if an earlier detection of regional tissue hypoperfusion would be provided to these patients. Differently from adults, in both neonates and infants, abdominal organs perfusion (kidney) can be monitored using the near infrared spectroscopy (NIRS). This device enables the detection of the states of organ hypoperfusion, allowing a rapid intervention to limit the cascade of multiple organs dysfunction and the development of shock [5–7]. NIRS uses nonpulsatile oximetry to determine venous-weighted oxy-hemoglobin saturation of the underlying regional tissue (rSO2) studied. In pediatrics generally two-site NIRS (brain–kidney) is used for the non invasive assessment of the cardiac output and of its autoregulation in the case of shock [6]. Normally tissue beds with high oxygen consumption (brain) have lower baseline rSO2, where tissue with little metabolic demand (kidney) have a higher baseline rSO2. Figure 1 shows a case of primary ACS for a Clostridium difficilis enterocolitis in a 6-month-old child (7 kg body weight) in which two-site NIRS (brain–kidney) was continuously used to manage the relation between cardiac output and IAP. This patient presented a pathologic change in brain and kidney saturation (dotted arrow) when IAP was *10 mmHg and diuresis was still 1.5 ml/kg/h. This state was not controlled with the medical therapy (deep sedation, neuromuscular M. Di Nardo (&) C. Cecchetti F. Stoppa N. Pirozzi S. Picardo Pediatric Intensive Care Unit, Children’s Hospital Bambino Gesu, Rome, Italy e-mail: matteo.dinardo@tin.it

Purpose Recent reports suggest that ultrasound-guided central venous cannulation may also be safe and effective in infants. This study aimed to evaluate the success and complications rate of this technique in infants weighing less than 5 kg. Methods We studied 45 infants, weighing less than 5 kg (mean weight: 2.9 ± 1.1 kg, median: 3.1) needing a central venous access for intensive care treatment. In all patients, venous access was obtained by ultrasound-guided cannulation of the internal jugular vein (IJV). Results Central venous cannulation was successful in all 45 infants. The right internal jugular vein (IJV) was used in most cases (92%). The IJV was antero-lateral to the carotid artery in 66% of patients, lateral in 28% and anterior in 6%. Although we recorded 10 complications (22.2%), only one was clinically relevant (one pneumothorax). The other complications were repeated venipunctures (n=4), kinking of the guidewire (n=3) and local venous hematomas (n=2). The time required for completing the procedure was 7 ± 4.3 min, while the mean time of central venous catheter permanence was 5.5 ± 8 days. There was a negative correlation between the patient's weight and the time needed for cannulation (pConclusions Our experience suggests that ultrasound-guided central vein cannulation can be performed by well-trained physicians in infants weighing less than 5 kg without relevant risks.

BACKGROUND: Preoperative renal function is an important risk factor in cardiac surgery for long-term and short-term outcomes. Renal function is best assessed by measuring or calculating the glomerular filtration rate (GFR). Several algorithms using the endogenous marker serum creatinine have been developed to estimate renal function. These include the Cockcroft and Gault and the modification of diet in renal disease (MDRD) formulae. The aim of this study was to compare the predictive power of the two formulae towards short-term outcomes after cardiac surgery, such as the length of intensive care unit (ICU) stay, the length of mechanical ventilation time, and the length of in-hospital stay. METHODS: One hundred and fifty patients undergoing cardiac surgery and not affected by renal failure were followed up until hospital discharge. We collected data before, during and after surgery. Before surgery data consisted of date of birth, sex, height, weight, plasma creatinine level; during surgery data consisted of type of intervention (including number of bypasses, if any), cardiopulmonary bypass time and aortic cross-clamp time; after surgery data consisted of length of ICU stay, mechanical ventilation time, length of in-hospital stay after intensive-care discharge (ward stay), incidence of acute renal failure (expressed as the need for dialysis) and mortality. The dataset was analyzed using Cox regression. RESULTS: The average mechanical ventilation time, ICU stay and ward stay were 11 h, 49 h and 10 days, respectively. After having adjusted for chronic obstructive pulmonary disease, diabetes and postsurgical dialysis, the GFR calculated with the Cockcroft and Gault formula appeared to be a predictor of ICU stay and mechanical ventilation time with very strong evidence (P = 0.002 and

Autogenous radial-cephalic direct wrist arteriovenous fistula (RCF), the gold standard for chronic dialysis, suffers from an elevated early failure rate (up to 20-50% with a pooled rate of 15.3%). Guidelines indicate that a small radial artery internal diameter (1.6-2 mm) is strongly predictive of this early failure. Microsurgery and preventive haemostasis have been reported to give excellent results in a paediatric population (children10 kg bw) and have shown a much lower early failure rate of 5-10%. Given these excellent results, we have used microsurgery along with preventive haemostasis in adult patients. We herein describe the results of RCF created in patients with a radial artery internal diameter1.6 mm.From November 2004 to December 2007, 28 RCFs were created in 28 patients with a distal radial artery internal diameter1.6 mm using microsurgery and preventive haemostasis. The median age was 68 and the male/female ratio was 6/22. The incidence of age65 years was 64%, hypertension 96%, diabetes 32.1%, obesity (BMI30) 35%, vascular disease 46%. The mean distal radial artery and cephalic vein internal diameters, measured with ultrasound examination, were 1.3 mm and 1.9 mm, respectively. Seventy-five percent of the patients were not yet on dialysis treatment; 19% of whom had a previous failed vascular access created elsewhere without microsurgery. The remaining 25% patients were on dialysis treatment with a temporary femoral catheter.All interventions ended with a patent anastomosis; no thrombosis occurred within the initial 24 h. The early failure rate was 14% (4 out of 28 patients). The causes of early failure were thrombosis1 week after surgery in one patient, lack of maturation (patent but unfunctional fistula) due to juxta-anastomotic vein stenosis in two patients and mid-vein stenosis in one patient. Treatment for all patients was proximalization of the anastomosis at the distal/mid forearm. Primary patency and secondary patency at 1 year were 68 +/- 10% and 96 +/- 5%, respectively.From our findings, we have shown that it is possible to create RCF in adult patients with a radial artery internal diameter of1.6 mm with an acceptable risk of early failure rate using microsurgery along with preventive haemostasis.