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In neonates, infants and young children central venous catheters are of vital importance during surgery as well as postoperative care. The benefit of ultrasonography seems to be very important for vascular access of the internal jugular (IJV), subclavian (SCV), femoral and even peripheral veins. Ultrasound-guided cannulation of the IJV increases the success rate, reduces the time to the successful puncture and decreases the inadvertent puncture of the carotid artery in children in comparison to the landmark-guided technique. Due to compression of the vessel by the approaching needle in neonates transfixing the vein and aspirating blood on withdrawal of the needle may be the preferred technique. The lack of space may prevent ultrasound-guided puncture of the SCV in very low birth weight infants. However, the location of the vein and its patency should always be determined via ultrasound prior to cannulation. After catheterization of the SCV the homolateral IJV is screened by the use of ultrasound to detect wrong guide wire migration. A clear and rapid visualization of visceral pleura movement against the parietal pleura during respiration via ultrasound indicates the absence of pneumothorax after cannulation. In the case of haemodynamic instability, ultrasound should be used to exclude pericardial effusion.

Aim: The aim of this study was to compare measured versus calculated venous cross-sectional area in healthy subjects in a standing and a lying position with normal breath-ing and during Valsalva manoeuvre., Method: Measurements were carried out in 30 venous segments (the common femoral vein CFV, the superficial femoral vein SFV, the greater saphenous vein GSV) of 5 healthy volunteers (4 female, 1 male) with a median age of 28.7 years (range 23.4-46.7 years) in supine and standing position, while normally breathing and during a standardised Valsalva manoeuvre. Venous diameters were measured from B-mode in longitudinal view while cross-sectional areas were planimetrically assessed from transverse B-mode as recorded on video (S-VHS). The mathematical calculation of areas followed the formula (0.5 diameter)2 x pi. All investigations were performed 3 times; mean values from these 3 measurements were used for further computation. Measurements were performed using the NIH Image 1.6 program., Results: Correlation coefficients r of the calculated versus the measured venous area while normal breathing in standing and in lying subjects were: 0.92 and 0.82 in the CFV, 0.92 and 0.84 in the SFV as well as 0.98 and 0.97 in the GSV, respectively. During Valsalva manoeuvre in standing and lying subjects the correlation coefficients r amounted to: 0.94 and 0.93 in the CFV, 0.92 and 0.94 in the SFV as well as 0.99 and 0.98 in the GSV, respectively., Conclusions: In healthy volunteers measured and calculated venous cross-sectional area at rest and during Valsalva manoeuvre correlate well. Correlation is numerically better in standing compared to lying subjects while normal breathing. Calculated venous area is accurate and can be used for further calculations.

The behaviour of the peripheral venous pressure was checked after starvation of the venous main vessel of the pelvic limb in 34 mongrel dogs in long-term course about 40 weeks. The influence of recanalisation processes on the pressure development was excluded by the ligature model. The pressure measurements took place continuously statically and dynamically in horizontal and in oblique posture. They produced a changed pressure characteristic with a chronically increased resting pressure and a decreased drop in pressure with load. The insufficient transport capacity of the spontaneously originated collateral circulation could be pointed out.

We investigated the topography between small arteries and the proximal Vena saphena magna after observations and extractions of specimens made during variectomies. Moreover we studied this region by anatomical preparation. During an operation a small artery with transvenous course had been observed. The obtained specimen were examined histologically. The developmental mechanism of such an unusual course of an artery is discussed.