Non-invasive imaging diagnosis of left renal vein compression causing hematuria. Part 1. Ultrasonography

Left renal veins of 100 out-patients were examined by transabdominal ultrasonography to evaluate its usefulness in determining left renal vein compression which is causing renal bleeding. Ultrasonography revealed the left renal vein in 86 patients. In 61 of the 86 cases, the internal cavity of left renal vein was opened at least in diastolic phase, but in 23 cases, the internal cavity was closed between the abdominal aorta and the superior mesenteric artery in both systolic and diastolic phases. In the remaining 2 cases, left renal vein was compressed at a point where it intersected the right renal artery. Left renal vein compression was observed in 18 (69%) of the 26 cases which had been classified as idiopathic renal bleeding and in 7 (26%) of the 27 cases which had urinary tract diseases causing hematuria. In 33 cases which did not have hematuria, left renal vein compression was not observed. These results suggest that diagnosis of left renal vein compression causing renal bleeding is possible by transabdominal ultrasonography.     

"胡桃夹症"临床症状和影像学表现的探讨(附13例报告)

目的：提高对“胡桃夹症”的诊断水平。方法：回顾性分析13例“胡桃夹症”患者的临床资料。结果：10例首发症状为血尿，2例首发症状为左侧阴囊内蚯蚓状肿物，以左侧精索静脉曲张就诊，1例首发症状为蛋白尿。1例女性患者伴月经量增大。男性患者均有左侧精索静脉曲张。血管多普勒超声提示左肾静脉通过腹主动脉和肠系膜上动脉之间有受压征象，径线1．6～6．1inin，平均2．64mm。肾门静脉段呈增粗改变，径线7．1～21．0mm，平均10．9mm。增强CT扫描横断面可见腹主动脉和肠系膜上动脉之间挤压左肾静脉，矢状面可见肠系膜上动脉与腹主动脉成锐角，其间的通道变窄。2例肾静脉造影提示左肾静脉过腹主动脉和肠系膜上动脉段处变窄。4例膀胱镜检查可见左侧输尿管口喷血。结论：血尿、蛋白尿、左侧精索静脉曲张是“胡桃夹症”的重要临床症状。多普勒超声、CT是“胡桃夹症”重要的无创性诊断方法。     

The "nutcracker phenomenon" with orthostatic proteinuria: case reports

The nutcracker phenomenon refers to compression of the left renal vein between the aorta and the superior mesenteric artery. Clinical features are hematuria, abdominal pain, left flank pain, pelvic or scrotal discomfort due to varicocele or ovarian vein syndrome. In this report, 2 patients with orthostatic proteinuria, in whom nutcracker phenomenon was detected as a cause, are presented. One of them had posterior nutcracker with also asymptomatic varicocele that was detected during ultrasonographic examination. Nutcracker phenomenon is a rare but important clinical condition that should be considered in the differential diagnosis of patients with proteinuria and hematuria.     

Nutcracker phenomenon: A new diagnostic method of multislice computed tomography angiography

OBJECTIVE: We evaluated 3-D computed tomography angiography (3-D CTA) in the diagnosis of the nutcracker phenomenon, and its significance in postoperative follow up. PATIENTS AND METHODS: Three-dimensional CTA was used to compare the anatomical relations of the left renal vein with the aorta and the superior mesenteric artery in patients with the nutcracker phenomenon and in a control group. Four patients with the nutcracker phenomenon received a surgical procedure of the transposition of the left renal vein. The 3-D CTA was used for all patients during postoperation follow-up testing. RESULTS: The 3-D CTA showed a compression of the left renal vein between the aorta and the superior mesenteric artery (SMA) and the abnormal acute angle between them. The angles and distances between the SMA and the aorta were 39.3 +/- 4.3 degrees and 3.1 +/- 0.2 mm in the patient groups and 90 +/- 10 degrees and 12 +/- 1.8 mm in the control groups, respectively. Differences in angles and distances were statistically significant between the two groups (P < 0.05). Surgical transposition of the left renal vein was performed successfully. Postoperative 3-D CTA revealed the distance between the SMA and the aorta was nearly normal. CONCLUSION: The reconstruction imaging of the renal vein by means of 3-D CTA revealed that unusual hematuria was due to compression of the left renal vein; therefore it may be a useful alternative imaging technique instead of conventional examinations. The non-invasive 3-D CTA may be a useful tool in the diagnosis of the nutcracker phenomenon and follow-up testing.     

Nutcracker syndrome. Report of a case and review of the literature

Nutcracker syndrome is caused by compression of left renal vein between the aorta and the superior mesenteric artery. This phenomenon results in left renal venous hypertension, left gonadal vein varices and unilateral hematuria. We report a typical case of nutcracker syndrome and we review the literature in an effort to explain this pathology.     

胡桃夹综合征的诊断和手术治疗(附3例报告)

目的:探讨胡桃夹综合征(NCS)的诊断与治疗。方法:NCS患者男2例,女1例,年龄14～23岁。临床主要表现为反复发作的血尿、蛋白尿和腰痛,1例并发左侧精索静脉曲张。多普勒彩色超声及CT示腹主动脉与肠系膜上动脉夹角处左肾静脉受压明显。3例患者均行左肾静脉移位术。结果:3例患者术后血尿或蛋白尿均消失,无并发症发生。术后6个月行多普勒彩色超声及尿液检查均未见异常。结论:NCS临床表现为反复发作的血尿或蛋白尿。多普勒彩色超声在NCS的诊断中具有重要价值。左肾静脉移位术是治疗NCS的有效方法。     

左肾静脉支架植入治疗胡桃夹综合征

目的探讨介入治疗胡桃夹综合征的效果。方法 4例胡桃夹综合征男性患者,年龄17～26岁,临床表现为肉眼血尿和镜下蛋白尿;B超示左肾静脉受压,狭窄处血流加快,CT示腹主动脉与肠系膜上动脉夹角处（〈30°）左肾静脉狭窄。对所有患者均采取介入治疗,行左肾静脉造影并测压后,经股静脉或颈静脉途径于左肾静脉植入长60mm、直径16～18mm自膨式血管支架。结果对4例患者介入治疗均取得成功。术后支架形态良好,血管受压现象消失,左肾静脉狭窄两端压力差由10～16mmHg下降为0～3mmHg,患者临床症状明显改善。随访6～12个月,除1例出现一过性镜下血尿外,余3例未见其他临床症状。结论采用介入方法治疗胡桃夹综合征具有微创、安全、治疗效果好的优点,对部分患者可替代手术治疗。     

Young woman with nutcracker syndrome without main clinic manifestation: Hematuria—Case report

IntroductionThe nutcracker syndrome occurs due to the compression of the left renal vein between the aorta and the superior mesenteric artery. The diagnosis of the syndrome is often difficult and under diagnosed. The main clinical manifestations are hematuria and pelvic or back pain.Presentation of caseA 25 years old female patient with severe abdominal pain in the lower abdomen without hematuria. Diagnosis with nutcracker syndrome after performing computed tomography. Presented the first episode of pain with 17 years old and was diagnosed at age 25.DiscussionIn the nutcracker syndrome anatomical changes do not generate specific symptoms, causing the disease to be underdiagnosed. In this syndrome, there is increased pressure on the left renal vein, generating several signs and symptoms, and hematuria is one of present. Our patient did not have hematuria. Because of common symptoms, it makes nutcracker syndrome difficult diagnosis, confusing with other diseases, especially with nephrolithiasis. It is usually diagnosed after exclusion of other diseases.ConclusionThe diagnosis of nutcracker syndrome is done after exclusion of other causes of chronic pelvic pain. In most cases, macroscopic and microscopic hematuria are present but was unobserved in this case. Making it more difficult diagnosis.     

Posterior nutcracker syndrome

Renal vein compression syndromes are rare causes of hematuria and can be divided into anterior and posterior nutcracker syndrome. When the left renal vein is compressed between the aorta and the superior mesenteric artery it causes anterior nutcracker syndrome. The posterior nutcracker syndrome is very rare and is considered when the left renal vein is compressed between the aorta and vertebral column. Symptoms of nutcracker syndromes may include intermittent left flank pain associated with hematuria, proteinuria, and sometimes with symptoms of pelvic congestion. Diagnosis is often difficult and plan for treatment is always challenging and requires careful evaluation of the patient's history and workup findings. We present a rare case report of a posterior nutcracker syndrome diagnosed in a young lady with long-standing symptoms that required surgical intervention.     

Left renocaval venous bypass with autologous great saphenous vein for nutcracker syndrome

Nutcracker syndrome results from left renal vein compression by the abdominal aorta and the superior mesenteric artery. The consecutively increased renal venous pressure results in hematuria, proteinuria, flank pain, left-sided varicocele, pelvic congestion, and others. We report a 25-year-old man with nutcracker syndrome who underwent successful left renocaval venous bypass with autologous great saphenous vein. The patient's condition clearly improved, with no clinical relapse after treatment. Ultrasound imaging showed patency of the venous bypass and decreased venous hypertension. This technique is a feasible choice for surgical treatment of nutcracker syndrome, with a low incidence of complications and satisfactory results.     

Renal nutcracker syndrome: Surgical options

Nutcracker syndrome is one of the abdominal venous entrapments, caused by compression of the left renal vein between the superior mesenteric artery and the abdominal aorta. Occasionally a retro-aortic left renal vein is compressed between the aorta and the vertebral body (posterior nutcracker syndrome). The renal vein distal to the compression is dilated and renal venous flow can be diverted toward the pelvis through an incompetent, refluxing, left ovarian or spermatic vein, in addition to drainage through retroperitoneal venous collaterals. In this article, we describe the different surgical and endovascular techniques that are used to treat this syndrome.     

Actitud expectante en el síndrome del cascanueces

Nutcracker syndrome is caused by compression of the left renal vein between the aorta and the superior mesenteric artery where it passes in the fork formed at the bifurcation of these arteries. The phenomenon results in left renal venous hypertension. The syndrome is manifested by left flank and abdominal pain, with or without unilateral haematuria. The nutcracker syndrome has been treated in various ways. We report one case of the syndrome and discuss the place of surveillance in its management.     

精索静脉髂外静脉分流术治疗胡桃夹综合征1例报道并文献复习

目的探讨胡桃夹综合征（NCS）的诊断及治疗方法。方法对1例NCS患者临床表现及诊断与治疗进行分析讨论。结果术后3月复查精子情况好转,蛋白尿消失,彩超示新建循环通路畅通。结论NCS临床表现复杂,诊断应将症状与辅助检查相结合,精索静脉髂外静脉分流是治疗NCS的方法之一。     

Endovascular management of nutcracker syndrome after migration of a laparoscopically placed extravascular stent

Nutcracker syndrome results from compression of the left renal vein between the superior mesenteric artery and the aorta, leading to symptoms of hematuria and left flank pain. Management options include endovascular or laparoscopic extravascular stent placement, which is very appealing given the minimally invasive nature of these procedures. We report a case of migration of a laparoscopically placed extravascular stent for nutcracker syndrome that was treated successfully by endovascular stent placement.     

不同术式治疗胡桃夹综合征继发左精索静脉曲张效果分析

目的探讨不同术式治疗胡桃夹综合征(NCS)继发左精索静脉曲张的临床效果。方法回顾性分析2016-08—2021-08郑州大学第一附属医院泌尿外科行左肾静脉(LRV)外支架固定术的60例NCS继发左精索静脉曲张的青少年患者的临床资料。按不同术式分为3组,各20例。A组行腔镜手术并联合左精索静脉高位结扎术,B组行腔镜手术联合开放左精索静脉高位结扎术,C组不处理左精索静脉曲张。比较3组患者的基线资料及临床效果。结果3组患者的基线资料以及增大腹主动脉与肠系膜上动脉间的夹角、降低血尿及蛋白尿的发生率差异无统计学意义(P>0.05);A组改善精子质量、减小精索静脉内径的效果均明显优于B组、C组,差异均有统计学意义(P<0.05)。结论对于NCS继发左精索静脉曲张患者,腔镜手术、开放手术,以及是否联合左精索静脉高位结扎术,均能增大腹主动脉与肠系膜上动脉间的夹角和降低血尿及降低蛋白尿发生率;但腔镜LRV外支架固定术联合左精索静脉高位结扎术在改善精子质量、减小精索静脉内径、降低精索静脉曲张复发率等方面,具有明显优势。     

Usefulness of renal CT scan for analysis of nutcracker phenomenon]

Among 24 patients with confirmed left renal bleeding, 11 were diagnosed of having nutcracker phenomenon (NP) on the basis of the results of renal venography and pull-back pressure from the left renal vein to the inferior vena cava. Renal CT scan was performed for these 11 patients, and its usefulness as a means of diagnostic analysis was studied. The following results were obtained. 1. The left kidney was scanned at 5-mm intervals. The mean distance between the anterior surface of the abdominal aorta (Ao) and the posterior surface of the superior mesenteric artery (SMA) was 4.5 +/- 0.6 mm in the NP group, while it was 13.9 +/- 6.4 mm in the control group (p < 0.01). 2. Regarding the morphology of the left renal vein (LRV), tapering dilatation, i.e., funnel-like dilatation, from the left side of Ao was seen in the NP group. In the control group, the left renal vein showed a club-like shape continuing to the inferior vena cava and showed no dilatation. 3. Vascular structures indicative of collateral vessels were observed around the LRV in the NP group. If renal CT scan is performed at 5-mm intervals, the following CT finding are thought to be indicative of the nutcracker phenomenon; (1) a distance of 5 mm or less between Ao and SMA and (2) tapered dilatation of the LRV. This study suggests that renal CT scan is useful for diagnostic analysis of the nutcracker phenomenon.     

Spontaneous aorto-left renal vein fistula: the "abdominal pain, hematuria, silent left kidney" syndrome

Spontaneous aorto-left renal vein fistula (ALRVF) is a rare occurrence; with this case, only 16 have been reported to date. Common features in patients with ALRVF include abdominal pain (81%), hematuria (100%), impaired renal function (85%), and nonvisualization of the left kidney (100%). Less common but also present in the majority of cases are a left sided bruit (73%), pulsatile abdominal mass (63%), and proteinuria (50%). Also important, 94% have a retroaortic left renal vein, unlike the six cases of traumatic ALRVF that have been reported. This magnifies the diagnostic value of contrast abdominal computed tomographic scanning, which demonstrates not only the anomalous location of the left renal vein but also the abdominal aortic aneurysm and poor enhancement of the left kidney. These findings rule out the possibility of the "nutcracker syndrome" (left renal vein compression between aorta and superior mesenteric artery). Although confirming the presence of a fistula by early caval opacification, aortography does not always distinguish ALRVF from the more common aortocaval fistula. This can be accomplished by Duplex scanning with deep probes and even preferably color coding of velocity signals. With such precise preoperative localization, surgical repair is relatively easy and safe.     

Nutcracker syndrome associated with severe anemia and mild proteinuria

A 70-year-old man was referred to our hospital with the chief complaint of gross hematuria. Urinalysis revealed gross hematuria (3+, RBC 100/HPF or more) and mild proteinuria (3+, 1.8 g/day) with no urinary casts. Computed tomography of the abdomen showed compression of the left renal vein between the superior mesenteric artery and the aorta. Ultrasonography showed an increased flow velocity at the stenotic portion of the left renal vein. An aortography and selective left renal arteriography showed that there was no evidence of tumor vessels or arterial abnormalities in the arterial phase. However, the venous phase revealed a stenosis of the left renal vein just lateral to the aorta as well as a reflux of contrast material toward the left gonadal vein which was dilated. In addition, cystoscopy revealed left ureteral bleeding. Based on these findings, we made the diagnosis of gross hematuria caused by nutcracker syndrome (NCS). We concluded that the main cause of the anemia and proteinuria in our patient was leakage of blood and this is confirmed by the relationship of red blood cells to protein in the urine because we proved whole blood and plasma protein loss in the urine by calculation. Fourteen months after discharge, both the gross hematuria and proteinuria spontaneously disappeared. This case strongly suggested that the first therapy for hematuria and proteinuria with NCS should be observation.     

Nutcracker syndrome and left unilateral haematuria.

The nutcracker phenomenon refers to compression of the leftrenal vein between the aorta and superior mesenteric artery.This phenomenon with its associated symptoms and signs is definedas nutcracker syndrome [1]. It occurs in relatively young andpreviously healthy people. The compression     

腹腔镜下左肾静脉外支架固定术治疗左肾静脉压迫综合征的临床分析

目的 探讨腹腔镜下左肾静脉外支架固定术治疗左肾静脉压迫综合征的临床疗效.方法 左肾静脉压迫综合征患者5例.男4例,女1例.年龄20～35岁,平均25岁.肉眼血尿3例,活动后加重,合并蛋白尿1例;左腰酸痛伴左精索静脉曲张2例.术前彩色多普勒超声及CT三维血管重建均提示左肾静脉压迫明显.扩张段与受压段直径比值均＞3.膀胱镜检查3例可见左输尿管口喷血尿.5例均于全麻下行腹腔镜下左肾静脉受压段外支架固定术治疗,术中用人造血管固定于下腔静脉与生殖静脉之间形成血管外支架以克服左肾静脉受压.结果 5例手术均顺利完成.手术时间65～70 min,平均67 min.术中出血量10～15 ml,平均13 ml.术中术后无明显外科并发症,术后恢复顺利,术后5～6 d出院.肉眼血尿消失3例,左精索静脉曲张减轻2例.术后随访9～39个月,平均28个月,1例术前肉眼血尿、术后仍有轻微镜下血尿,4例尿常规检查正常.5例其余症状均消失,超声检查示左肾静脉血流通畅、受压现象消失.结论 腹腔镜下左肾静脉外支架固定术采用人造血管环绕左肾静脉抵抗肠系膜上动脉压迫,是治疗左肾静脉压迫综合征的一种可供选择的微创技术,手术简单、方便、安全有效,创伤小、痛苦少、恢复快.