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This study aimed to describe the efficiency and longevity of arteriovenous fistula (AVF) for hemodialysis (HD) in children weighing ≤20 kg. We collected data of all AVFs created using microsurgery techniques between 1988 and 2015. Success was considered as the ability to use the AVF for HD. Primary and secondary patency rates were measured. Forty-eight AVFs (35 forearm, 13 upper arm) were created in 41 children with a median weight of 13.5 kg (range 5.5–20). The need for a second AVF was significantly higher in younger and thinner children at the time of AVF creation (p = 0.046 and p = 0.019, respectively). Successful use for HD occurred in 42 AVFs (87.5%), while six (12.5%) resulted in failure for early thrombosis or nonmaturation. Median time to first cannulation was 18.8 weeks (range 2–166.3). Primary and secondary patency rates at 1, 5, and 10-year follow-ups were 54.2%, 29.2%, and 13.7%; and 85.4%, 57.7%, and 33%, respectively. Almost one third of thromboses after first AVF cannulation were observed at kidney transplantation (KT) perioperatively. At the end of the follow-up (median duration 5.07 years, range 0–17.95), one patient was still on HD via AVF, two died of unrelated reason, and 38 were transplanted—one of whom returned to HD with a new AVF. AVF using microsurgery techniques is feasible in young children, showing an early failure rate of 12.5%. Time to first cannulation may be rather long, but secondary patency is excellent. Thrombosis rate is high during KT.

L’emodialisi richiede un accesso vascolare che permetta delle connessioni ripetute al rene artificiale. La fistola arterovenosa nativa e il migliore accesso vascolare. I bypass arterovenosi protesici, indicati in caso di impossibilita di creare un accesso nativo, sono gravati da stenosi recidivanti dell’anastomosi venosa. I cateteri venosi centrali, insostituibili in caso di urgenza, consentono di attendere la maturazione degli accessi vascolari, ma si complicano con infezioni gravi e stenosi venose centrali che minacciano gli accessi vascolari futuri. Le procedure endovascolari permettono la gestione di un gran numero di complicanze, benche la chirurgia mantenga un ruolo certo nel trattamento delle stenosi juxta-anastomotiche all’avambraccio, degli iperflussi e delle ischemie.

L’emodialisi mira a depurare il sangue e a ridurre l’inflazione idrosodica dei pazienti con insufficienza renale cronica. Essa richiede un accesso vascolare che permetta delle connessioni ripetute al rene artificiale. La fistola arterovenosa nativa, descritta da circa 50 anni, e il migliore accesso vascolare, benche richieda un periodo di maturazione prima dell’utilizzo. I bypass arterovenosi protesici sono gravati da stenosi ricorrenti dell’anastomosi venosa. I cateteri venosi centrali, insostituibili in caso di urgenza, si complicano con infezioni gravi e stenosi venose centrali che minacciano gli accessi vascolari futuri. L’anestesia locoregionale permette la realizzazione degli accessi in chirurgia ambulatoriale nella maggioranza dei casi. La microchirurgia semplifica molto la preparazione delle anastomosi distali nell’adulto e la rende possibile nei bambini. L’eco-Doppler e l’esame di riferimento nella valutazione pre-, intra- e postoperatoria. L’angiografia e le procedure endovascolari permettono la gestione di un gran numero di complicanze, benche la chirurgia conservi un ruolo certo nel trattamento delle stenosi juxta-anastomotiche all’avambraccio, degli iperflussi e delle ischemie.

Introduction Arteriovenous autologous fistula (AVF) is the best vascular access (VA) for hemodialysis but its feasibility in smaller children remains a surgical challenge. This study aims to describe a single-center experience regarding the efficiency, longevity and associated morbidities of AVF created in children weighting ≤ 20 kg. Material and methods We collected data of all AVF created using microsurgery techniques after preoperative ultrasound vascular mapping between 1988 and 2011. Primary patency (PP) was defined as the interval time from VA creation until any intervention designed to maintain or re-establish patency or until VA abandonment (failure or transplantation). Secondary patency (SP) was defined as the interval time from creation to VA abandonment. Results Fifty AVF (36 distal, 14 proximal) were created in 40 children with a median weight of 13 kg (range 6 to 22). A total of 22 children were already on extra-renal epuration: 18 on HD via central venous catheter and 4 on peritoneal dialysis. Early complications during the first month after AVF creation were observed in 8 AVF, 6 thrombosis, which were abandoned, and 2 non maturations (1 re-operated successfully). Median time to maturation (first utilization in HD) was 4 months. Secondary complications observed between the first month after AVF creation and transplantation or VA failure were the following: 18 thrombosis (39% of which occurred during transplantation surgery), 22 stenosis (15 corrected by angioplasty, 4 by surgery whether 3 ended to AVF failure) and 3 high blood flow rate (1600, 1850, 2100 mL/min/1,73 m2) without evidence of cardiac complications. Median duration of PP and SP were 7 and 17 months respectively. Conclusions In our experience, AVF is feasible in younger children with 86% of success. Time to maturation is longer than in older children but SP after creation is excellent. Attention should be paid during transplantation surgery, as thrombosis rate is considerably high.

Resumen Hace aproximadamente 30 anos, Brescia y Cimino publicaron los primeros trabajos sobre las fistulas arteriovenosas [4]. La experiencia y la perspectiva en el tiempo permiten afirmar que estas fistulas son actualmente el mejor procedimiento para crear un acceso vascular que pueda utilizarse en forma repetida para la hemodialisis. En el campo tecnico se realizaron importantes progresos que permitieron mejorar la realizacion de las fistulas. Asi, el aporte del microscopio operatorio, la utilizacion de tecnicas microquirurgicas y de la hemostasia preventiva con torniquetes neumaticos permiten crear fistulas arteriovenosas en vasos de muy pequeno calibre, lo cual es muy importante, sobre todo en el nino [1]. La aparicion de materiales protesicos permite paliar, en ciertos casos, una deficiencia de la red vascular superficial. Los cateteres venosos centrales permiten un acceso poco invasivo a la circulacion sanguinea (con frecuencia percutaneo), en general provisorio. La via subclavia fue abandonada. La via yugular interna no esta exenta de riesgos que aun deben ser evaluados [11]. Los progresos de la anestesia locorregional contribuyeron a que este tipo de cirugia sea mas seguro y permitieron realizar muchas intervenciones en forma ambulatoria. En el campo del control de las fistulas arteriovenosas, la ecografia Doppler es de gran ayuda para detectar las estenosis y apreciar el flujo de manera no invasiva [7, 8]. La radiologia intervencionista representa igualmente un progreso en el tratamiento de ciertas estenosis que siguen a una fistula arteriovenosa. La frecuencia de la insuficiencia renal terminal y la diferencia entre la cantidad de receptores y de donantes de injertos renales imponen un perfecto conocimiento de los metodos empleados para crear accesos vasculares destinados a la hemodialisis. Tambien se utiliza la fistula arteriovenosa para afecciones diferentes de la insuficiencia renal cronica, las cuales necesitan un acceso vascular repetido y prolongado por muchos anos, sobre todo en el nino, como son la drepanocitosis homocigotica, la hipercolesterolemia familiar, anomalias digestivas tratadas por medio de nutricion parenteral continua y la mucoviscidosis.

Resumen Las complicaciones precoces de los accesos vasculares arteriovenosos en la hemodialisis cronica deben evitarse por medio de una correcta evaluacion preoperatoria clinica y paraclinica (Doppler y angiografia), y una tecnica quirurgica realizada con precision (hemostasia preventiva y microcirugia). Las complicaciones secundarias de las fistulas arteriovenosas son mucho menos frecuentes que las de las derivaciones protesicas. Las estenosis yuxtaanastomoticas de las fistulas distales, que son tardias, se tratan reparando quirurgicamente la anastomosis arteriovenosa. Las estenosis de la anastomosis venosa de las derivaciones, que aparecen precozmente, deben detectarse y tratarse generalmente por medio de angioplastia endoluminal percutanea. Las derivaciones trombosadas pueden desobstruirse de forma percutanea junto con la realizacion de la angioplastia endoluminal de la anastomosis venosa. Si aparece una complicacion infecciosa, no hay que dudar en sacrificar la estructura, sobre todo si hay protesis. Las complicaciones isquemicas son debidas al robo vascular inherente a toda fistula y a una red arterial de mala calidad. No siempre es posible o eficaz la reduccion del robo y el tratamiento de las anomalias arteriales. Tambien en estos casos, debe tomarse rapidamente la decision de cerrar la estructura arteriovenosa y recurrir a los cateteres venosos centrales, siempre que sea posible de forma temporal. Se han propuesto diversas soluciones originales para los casos de fistulas con flujo elevado y repercusion cardiaca.

Microsurgery gives much better immediate and long term results than classical surgery for the creation of direct arteriovenous fistulae, the best chronic access to blood in children.

Central venous stenosis is a complication of central vein catheter insertion through the internal jugular or the femoral vein in haemodialysed patients with non-functioning arteriovenous angio-access. The frequent complication is important limb swelling after subsequent creation of upstream arteriovenous fistula or graft. Closure of the fistula may be necessary, especially if creation of a new access is possible on the opposite limb. Surgical conservative treatment may be indicated. Percutaneous transluminal angioplasty is used first with good short-term results. Prevention of central venous stenosis by infrequent use of central venous catheter is of the utmost importance.

Expression of NG2 has been reported in the majority of paediatric acute leukaemia (AL) cases with MLL rearrangement. We demonstrated 7. 1 positivity in 2/3 paediatric and 4/11 adult MLL rearranged acute myeloid leukaemia (AML) but in 0/28 adult AML without MLL rearrangement, thus extending the 100% specificity to adult cases. Positivity correlated with stage of maturation arrest since it was found in 0/6 immature AML but in 6/8 monoblastic cases. These data demonstrate that, if NG2 expression in AL is the (in)direct result of MLL rearrangement, such activation is restricted to a monoblastic population in AML. They also have practical implications for NG2 diagnostic screening strategies.

The rapid detection of chromosome band 8q24 rearrangements, including classical translocations involving MYC and variant 3' translocations, is important for the accurate diagnosis and appropriate treatment of lymphoid malignancies. We have identified and characterized a CEPH YAC, 934e1, which extends from at least 190 kbp upstream to over 280 kbp downstream to MYC, allowing detection of classical t(8; 14)(q24;q32) and variant t(8;22)(q24;q11) and t(8;14)(q24;q11), extending distal to PVT1 and therefore, by extrapolation, to BVR1. This YAC also allowed clarification of complex chromosome 8 abnormalities and the identification of translocations in interphase nuclei. A second CEPH YAC, 904c3, previously shown to contain the PVT1 locus but not MYC, allowed distinction between translocations occurring centromeric and telomeric to MYC. Use of the 934e1 YAC will aid classification of a variety of lymphoid proliferations and further characterization of rearranged cases with the 904c3 YAC will simplify mapping of their diverse breakpoints.

The TAL1 gene is disrupted by translocation or deletion (tal(d)) in up to 30% of T-cell acute lymphoblastic leukaemia (T-ALL), leading to aberrant transcriptional activation, as a SIL-TAL1 fused transcript in tal(d). It has been suggested that TAL1 transcription occurs in approximately 50% of a T-ALLs without apparent rearrangement. SIL-TAL1 was positive in 15/60 (25%) of T-ALL, whereas wild-type TAL1 transcripts were detected in all 13 SIL-TAL1 and in 19/43 (44%) T-ALL without SIL-TAL1. To investigate the cellular origin of TAL1 we exploited the fact that GATA1 and TAL1 are co-ordinately expressed in non-lymphoid haemopoietic cells, whereas only the latter is found in T-ALL. GATA1 was detected in 10/23 (43%) TAL1-negative T-ALLs but in 17/19 (89%) 'unexplained' TAL1-positive cases, suggesting a common non-lymphoid cellular origin. Immunocytochemical analysis with a TAL1-specific monoclonal antibody showed nuclear expression in the blasts of 10/34 (29%) cases, including 8/10 SIL-TAL1+ and two RT-PCR TAL1+, SIL-TAL1- cases. In the remaining cases TAL1 expression was restricted to a minor population (5%) of larger, strongly TAL1-positive cells which comprised erythroid cells, CD34+ CD3- precursors and an unidentified TAL1+ CD45- population which morphologically resembled monocytes/macrophages. We therefore suggest that appropriate diagnostic evaluation of T-ALL should include molecular detection of SIL-TAL1 transcripts and in situ immunocytochemical detection of TAL1 protein expression by leukaemic blasts. This approach will enable accurate analysis of the prognostic significance of TAL1 deregulation in T-ALL.

To the Editor: Aplan et al[1][1] recently reported a site-specific DNA cleavage induced by topoisomerase II (Topo II) inhibitors within the MLL gene breakpoint cluster region on chromosome 11q23. The finding was initially identified by Southern blot analysis of circulating blasts taken from a case

We describe a case of late perforation of the superior vena cava by a hemodialysis catheter inserted via the left internal jugular vein. This resulted in extravasation of blood. Malposition of the catheter was confirmed by CT scan. Removal of the catheter resulted in rapid resolution of symptoms. Confirmation of correct placement of central venous catheter must be obtained by chest X-ray contrast study.

This report describes the clinical spectrum and outcome of the hemophagocytic syndrome (HS) in 5 HIV infected patients. All 5 patients presented with fever, hepatomegaly and/or splenomegaly, confusion or coma and respiratory symptoms. Severe anemia was associated with thrombocytopenia and with neutropenia in 4 cases. Diffuse intravascular coagulopathy was present in 2 cases. Liver function tests were abnormal in three patients. The diagnosis of HS was made 2 to 12 weeks after the onset of symptoms and required in most patients repeated examinations of the bone-marrow, showing infiltration by histiocytes with prominent phagocytosis of blood cells. In one case this infiltration was not seen in the bone-marrow but only in the liver and the spleen. Varicella, mycobacterium infection, oesophageal candidiasis, Kaposi sarcoma were observed in the evolution of 3 patients. Anaplastic large cell Ki-1 lymphoma was present in one case. Four patients died as a result of complications of HS. The one patient with lymphoma survived.

Although subclavian vein cannulation is more and more avoided for temporary angioaccess in hemodialysis patients may still now present stenosis or thrombosis of this catheterized central vein. Complications may appear, sometimes severe, after creation of an ipsilateral arteriovenous fistula. It is important to treat them but also to conserve the new created vascular access, in order to maintain these patients as long as possible on hemodialysis treatment. According to the circumstances, different procedures are used, and among them, the axillary-contralateral internal jugular vein crossing bypass as here reported.

In chronic haemodialysis the arteriovenous fistula is the angioaccess that has the longest survival. Its surgical creation has been considerably improved by microsurgery, notably in children. A sufficient time lag between the creation and use of the fistula is of paramount importance. The arteviovenous bridge-graft is used when the superficial venous system has been destroyed. Its survival is jeopardized by the risk of stenosis of the venous anastomosis and by the risk of infection. Venous catheterization through the internal jugular vein (never through the subclavian vein) is a temporary solution pending the arteriovenous approach; it is sometimes a permanent, but then highly risky, solution.

Three hundred and eighty children underwent 434 angioaccesses. Of these angioaccesses, 113 were constructed in 74 children weighing under 10 kg. Most accesses (n = 340) were distal arteriovenous fistulae (AVF). After microsurgery there was a 96% immediate patency. Seventy percent of AVF, excluding distal ulnarbasilic AVF, were functional, sometimes after secondary superficialization of the vein. Eighty-five per cent of the distal radial-cephalic AVF are still patent after 2 years, 60% are still patent after 4 years. These radial-cephalic AVF required 65 repeat anastomoses, and 12 ligations of the proximal-radial artery in order to reduce to 50% the high blood flow (pre-reduction average index = 900 ml/min per m2. The patency rate of arteriovenous-bridge grafts was not encouraging. The severity of stenoses in the proximal-venous trunks, sometimes related to previous catheterization, is emphasized. Advantages of the radial-cephalic wrist AVF in children are highlighted.

The authors study the consequences of amputation of the radial artery in order to create a Chinese forearm graft on the blood supply and innervation of the upper limb. After a brief review of the anatomy, the haemodynamics of the upper limb are studied in detail. Preoperative assessment by Hallen's test is generally sufficient. Postoperatively, pulsed Doppler studies provide the most useful information. Compensatory development of the interosseous artery is always observed and, in seven out of nine cases, this is associated with a marked increase in the blood flow in all of the arteries of the upper limb, especially in the hand. Of all of the methods of investigation available, this examination is able to demonstrate the safety of forearm grafts in the very great majority of cases.