Kim Woo Sun, Cheon Jung-Eun, Kim In-One, Kim Seung Hyup, Yeon Kyung Mo, Kim Kwang Myung, Choi Hwang
Department of Radiology, Seoul National University College of Medicine and the Institute of Radiation Medicine, SNUMRC, Seoul National University Hospital, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea.
Radiology. 2006 Oct;241(1):228-34. doi: 10.1148/radiol.2411050271. Epub 2006 Aug 14.
To evaluate prospectively the hemodynamic state of the left renal vein with Doppler ultrasonography (US) and venography in pediatric patients with varicocele to assess the "nutcracker phenomenon."
The institutional review board considered this study ethically sound, and parental informed consent was obtained for all subjects. Doppler US of the left renal vein was performed in 27 consecutive boys with varicocele (age range, 7-15 years; mean, 11.9 years) and in 20 boys without varicocele as control subjects (age range, 7-17 years; mean, 11.4 years). Doppler US was used to evaluate left renal vein diameters and peak velocities in the proximal left renal vein near the renal hilum and in the left renal vein between the aorta and superior mesenteric artery (aortomesenteric portion). The diameter ratios and peak velocity ratios between two sites were obtained. For statistical comparison of results, the t test was used. Left renal venography and renocaval pressure measurement were performed in 13 patients with varicocele. The Fisher exact test was used to evaluate the associations between the nutcracker phenomenon (renocaval pressure gradient >/=3 mm Hg) and the development of collateral veins.
The diameters of the proximal left renal vein and the peak velocities in the aortomesenteric portion of the left renal vein were significantly different between the varicocele group and the control group (P < .001). The diameter ratios (5.7 +/- 1.8 [standard deviation]) and peak velocity ratios (5.2 +/- 2.6) in patients with varicocele were significantly higher than those in control subjects (3.5 +/- 1.0 and 3.1 +/- 0.8, respectively) (P < .005). According to findings at left renal venography (n = 13), 10 patients (77%) met the criteria for the nutcracker phenomenon. The nutcracker phenomenon was significantly associated with the development of collateral veins (P = .035).
Doppler US and venography of the left renal vein can show hemodynamic changes of the left renal vein and depict the presence of the nutcracker phenomenon in pediatric varicocele.
前瞻性地应用多普勒超声（US）和静脉造影术评估精索静脉曲张患儿左肾静脉的血流动力学状态，以评估“胡桃夹现象”。
机构审查委员会认为本研究在伦理上合理，并获得了所有受试者家长的知情同意。对27例连续的精索静脉曲张男孩（年龄范围7 - 15岁；平均11.9岁）及20例无精索静脉曲张的男孩作为对照受试者（年龄范围7 - 17岁；平均11.4岁）进行左肾静脉多普勒超声检查。应用多普勒超声评估左肾静脉肾门附近近端左肾静脉以及主动脉与肠系膜上动脉之间的左肾静脉（主动脉 - 肠系膜部分）的直径和峰值流速。获取两个部位之间的直径比和峰值流速比。为进行结果的统计学比较，采用t检验。对13例精索静脉曲张患者进行左肾静脉造影和肾腔静脉压力测量。采用Fisher精确检验评估胡桃夹现象（肾腔静脉压力梯度≥3 mmHg）与侧支静脉形成之间的关联。
精索静脉曲张组与对照组之间，近端左肾静脉直径及左肾静脉主动脉 - 肠系膜部分的峰值流速存在显著差异（P < .001）。精索静脉曲张患者的直径比（5.7 ± 1.8[标准差]）和峰值流速比（5.2 ± 2.6）显著高于对照受试者（分别为3.5 ± 1.0和3.1 ± 0.8）（P < .005）。根据左肾静脉造影结果（n = 13），10例患者（77%）符合胡桃夹现象标准。胡桃夹现象与侧支静脉形成显著相关（P = .035）。
左肾静脉多普勒超声和静脉造影可显示左肾静脉的血流动力学变化，并描绘小儿精索静脉曲张中胡桃夹现象的存在。
