Vascular ultrasound in pediatrics: utility and application of location and measurement of jugular and femoral vessels.

OBJECTIVE: To measure the depth (D p) and diameter (D m) of the internal jugular vein (IJV), femoral vein (FV), and femoral artery (FA) in pediatric patients to evaluate the clinical implications. METHODS: This study included 125 pediatric patients. All of them underwent bilateral ultrasound study of vessels and were classified into three groups based on anthropometric and demographic parameters. RESULTS: Measured mean D p values were: 0.72 (0.34) cm for the FA, 0.79 (0.35) cm for the FV, and 0.77 (0.24) cm for the IJV. Mean antero-posterior D m values were: 0.37 (0.17) cm for the FA, 0.42 (0.22) cm for the FV, and 0.59 (0.23) cm for the IJV. D p and D m increased with age (A), weight (W), height (H), and body surface area (BSA). In the lower ranges of these variables, D p was similar for all three studied vessels (0.6-0.7 cm). In the higher ranges, femoral vessel D p values (1.1-1.2 cm) were larger than jugular ones (0.9 cm). Additionally, in these low ranges, IJV D m values were larger than femoral ones (0.45-0.50 vs. 0.25 cm). In the higher ranges, diameter values were similar (0.6-0.7 cm). CONCLUSIONS: In pediatric patients, major vessels can be located and their depth and diameter measured by vascular ultrasound. In younger patients, jugular and femoral vessels had similar depth values; in older ones, they had similar diameters. Ultrasound measurements in pediatric patients could facilitate the choice of the vessel to be cannulated, the catheter diameter, and the length of the needle to be used. Vascular canalization of IJV may be recommended as the first choice because of its low depth and large diameter.

Lentiviral vector mediated expression of Bax and hepatocyte growth factor inhibits vein graft thickening in a rabbit vein graft model.

Vein graft failure caused by vein graft thickening of the arterialized vein after bypass surgery is a main problem in clinical vascular surgery. Gene therapy is increasingly being recognized as a relevant treatment option for vein graft failure. In this study, we aimed to develop a novel recombinant lentivirus for the delivery of hepatocyte growth factor (HGF) and Bax in a rabbit vein graft model of bypass grafting. A bypass model was made in rabbits using the right jugular vein interposed end-to-end to the ipsilateral carotid artery. A lentivirus vector harboring HGF and Bax cDNAs (Lenti-HGF-Bax) was constructed and transduced into the venous grafts. Vein grafts were stained with hematoxilyn and eosin, and Masson. HGF and Bax expression in vein grafts was detected by immunohistochemical and Western blot analysis. Our results showed that vein graft thickening was reduced by 47.2 ± 7.4% in lenti-HGF-Bax treated rabbits, compared to controls. Meanwhile, the ratio of intima/media area was reduced in lentil-HGF-Bax treated rabbits, compared to controls. The number of HGF and Bax positive cells was increased in vein grafts from rabbits treated by lenti-HGF-Bax, compared to those from controls. Furthermore, protein levels of HGF and Bax were both significantly increased in grafts derived from rabbits treated by lenti-HGF-Bax, compared to those from control. In conclusion, Lenti-HGF-Bax inhibits vein graft thickening in vein grafts and is a promising agent for preventing vein graft failure.

The relationship between the internal jugular vein and common carotid artery in the carotid sheath: the effects of age, gender and side.

The internal jugular vein is often used for central venous catheter placement. The variations in the location of this vein along the major neck vessels (in the carotid sheath) may account for unsuccessful cannulations or iatrogenic arterial injuries. The aim of this study was to delineate the relation of the internal jugular vein and common carotid artery in the lower neck, and to assess the effects of age, gender and side on these anatomical structures. Two-dimensional ultrasonographic examinations of the right and left supraclavicular triangle were performed in 219 adult individuals who had no history of neck surgery or known pathology. The location of the internal jugular vein in relation to the common carotid artery was recorded. An anterolateral location of the internal jugular vein was the most common configuration observed on both sides (84% right side and 91.8% left side) followed by the lateral (14.2% right and 6.4% left) and anterior (1.4% right and 1.8% left) locations. A single case of a medial internal jugular vein was observed on the right side (0.23% of both sides). Subjects with a laterally located internal jugular vein were older than those with an anterolateral configuration (P<0.01). No gender differences were found with regard to these two configurations (P=0.867). The laterally located internal jugular vein was more frequent on right sides (P=0.007). Such information may be potentially useful for clinicians who are managing critically ill patients or patients undergoing hemodialysis.

Vein and artery growth after anastomosis with vascular closure staple clips vs interrupted polypropylene suture: application in pediatric vascular surgery.

BACKGROUND/PURPOSE: Alternatives are still being sought in vascular surgery to address the problem of arrested growth after anastomosis in growing vessels, and opinions differ widely regarding the most suitable technique. This study compared vascular growth and permeability after anastomosis using the latest-generation vascular closure staple (VCS) system and the conventional suture technique to ascertain which approach yielded better results. METHODS: Thirty 55-day-old lambs underwent end-to-end anastomosis of the carotid artery and jugular vein. Serial ultrasonography and angiography were carried out over the ensuing 6-month growth period, after which lambs were euthanized. RESULTS: Both VCS clips and polypropylene suture allowed longitudinal and transverse vessel growth; however, longitudinal growth was significantly greater in clip-closed vessels than in either sutured or untreated vessels. CONCLUSIONS: The results obtained for vascular growth and permeability suggest that VCS clips may provide a suitable alternative to conventional suture in pediatric vascular surgery.

A possible role of initial cell death due to mechanical stretch in the regulation of subsequent cell proliferation in experimental vein grafts.

The proliferation of vascular cells contributes to the formation of neointima and hypertrophy of the blood vessel wall. Here we show that mechanical stretch possibly regulates the proliferation of vascular cells via the mediation of cell death in a rat vein graft model. The wall of vein grafts is subject to a suddenly increased mechanical stretch due to exposure to arterial blood pressure. Such a stretch induces rapid cell death with a reduction in cell density by approximately 60% within the first day after surgery. The initial cell death was followed by an increase in the percentage of proliferating cells, as shown by a BrdU incorporation assay (1.55 +/- 1.27%, 8.48 +/- 2.27%, 11.93 +/- 2.36%, 6.36 +/- 1.77%, and 5.60 +/- 1.46% at days 1, 5, 10, 20, and 30, respectively). When mechanical stretch was reduced by restraining the vein graft using a polytetrafluoroethylene sheath, the percentage of proliferating cells reduced significantly (0.76 +/- 0.76%, 1.70 +/- 0.46%, 1.29 +/- 0.56%, 0.99 +/- 0.83%, and 0.47+/-0.52% at days 1, 5, 10, 20, and 30, respectively). A further reduction in cell density, induced by local administration of a cell death inducer ceramide to experimental vein grafts (without sheath), enhanced subsequent cell proliferation. In contrast, a prevention of cell death, induced by local administration of a cell death inhibitor tetrapeptide-aldehyde DEVD-CHO to experimental vein grafts (without sheath), significantly reduced subsequent cell proliferation. These results suggest that mechanical stretch induces cell death, which possibly mediates subsequent cell proliferation in the present model.

Significance of chymase-dependent angiotensin II-forming pathway in the development of vascular proliferation.

BACKGROUND: Vascular tissues of humans and dogs contain chymase as an angiotensin II-forming enzyme. In this study, we investigated whether chymase-dependent angiotensin II formation plays a crucial role in the development of vascular proliferation in dog grafted veins. METHODS AND RESULTS: The right external jugular vein of dogs was grafted to the ipsilateral carotid artery. As a control group, the right external jugular veins in dogs that had not received grafts were used. In the chymase inhibitor-treated group, the vein was infiltrated with 10 micromol/L Suc-Val-Pro-Phe(P)(OPh)(2) and was grafted to the carotid artery. In the placebo-treated group, ACE activity in the grafted veins was significantly lower than that in the control veins up to 7 days after the operation, whereas chymase activity was increased significantly. After 7 days, the mRNA levels of collagen I, collagen III, and fibronectin, all of which are induced by an increase of angiotensin II action, were significantly increased in the grafted veins, and the intima-media ratio of the grafted veins was also increased. In the chymase inhibitor-treated group, the chymase activity in the grafted veins 7 days after the operation was suppressed to 12.1%. The elevated mRNA levels of fibronectin, collagen I, and collagen III in the grafted veins were significantly suppressed by treatment with the chymase inhibitor, and the intima-media ratio was also decreased significantly. CONCLUSIONS: We demonstrate for the first time that chymase-dependent angiotensin II formation plays an important role in the development of vascular proliferation in the grafted veins.

Absorbable suture improves growth of venous anastomoses.

Growth of vascular anastomoses is desirable in pediatric vascular surgery, especially in pediatric organ transplantation. Although absorbable suture has been shown to be superior to nonabsorbable suture in permitting growth of arterial anastomoses, the optimal suture material for venous anastomoses has not been established. To examine this in a porcine model, we performed bilateral primary end-to-end anastomoses of transected external jugular veins in 10, 4-week-old piglets. In each piglet one anastomosis was constructed with continuous absorbable 8-0 polyglyconate suture, whereas the contralateral anastomosis was constructed with continuous nonabsorbable 8-0 polypropylene suture. After 6 months the veins were excised, pressure fixed at 15 mm Hg for 2 hours, and examined grossly and histologically. Vein diameter was measured by contrast radiography at the anastomosis and 1 cm proximal and distal to the anastomosis. Vein cross-sectional area 1 cm from the anastomosis was similar in the two groups: polyglyconate 95.7 +/- 12.3 mm2 versus polypropylene 95.3 +/- 9.7 mm2. However, polyglyconate anastomoses had greater cross-sectional area (polyglyconate 72.8 +/- 7.9 mm2 vs polypropylene 51.8 +/- 6.0 mm2; p < 0.05). In addition, at 6 months polyglyconate anastomoses had a greater percentage of growth (polyglyconate 207% vs polypropylene 118%; p < 0.05) compared with native vein cross-sectional area (23.7 +/- 0.39 mm2) from control pigs at 4 weeks of age. On histologic examination, polyglyconate had dissolved entirely in six cases and was present but in varying degrees of dissolution in the other four; in contrast, polypropylene was identifiable at all anastomoses.(ABSTRACT TRUNCATED AT 250 WORDS)

[The longitudinal increase of the internal jugular vein and the upper v. cava as measured between the mastoid to the heart: parameter for timing the re-operation after ventriculocardiostomy (author's transl)]. / Das Längenwachstum der Vena jugularis interna und der Vena cava superior vom Processus mastoideus zum Herzen. Ein Parameter für den Zeitpunkt notwendiger Revisionen nach Ventrikulokardiostomien

Some time after ventriculo-cardiostomy in children with hydrocephalus the cardiac catheter is retracting out of the right atrium into the upper veins due to the increase of body length during growth. This might endanger proper functioning of the valve. Therefore most authors are in favour of a prophylactic elongation of the catheter by re-operation. In order to roughly predict the time for re-operation we measured course of the catheter in 4120 children. As a basis for long time supervision of children with this shunt operation we thus propose a curve of length increase of the blood vessels concerned, based on our data, in connection with the known curve of length increase of the body.