Inferior vena cava thrombosis as a possible cause of nephrotic-range proteinuria: two case reports

Background Nephrotic-range proteinuria is a common reason for nephrological consultation in clinical practice. The differential diagnosis is wide, and generally focuses on different forms of glomerulonephritis, but other causes should not be overlooked, as illustrated in this article. Case presentations We report two female patients with nephrotic-range proteinuria. In the first case, a 46 year old Caucasian patient who suffered from extreme obesity (Body mass index (BMI) 77 kg/m2), acute kidney injury and nephrotic-range proteinuria were discovered during an emergency consultation for acute abdominal pain. The second patient (aged 52, also Caucasian) developed stage 4 chronic kidney disease and nephrotic proteinuria (protein/creatinine ratio 1821 g/mol) after accidental rupture of the inferior vena cava during a gastric bypass operation. On split-urine collection, both had a much higher degree of proteinuria during the day than during the night, compatible with orthostatic proteinuria. At further work-up, inferior vena cava thrombosis was diagnosed in both patients, whereas renal veins were patent. Discussion After simple anticoagulation in the first case, and anticoagulation plus endovascular recanalization in the second, there was almost complete resolution of the orthostatic proteinuria and a strong improvement of the estimated glomerular filtration rate in both patients. These cases highlight that nephrotic-range proteinuria can be linked to inferior vena cava thrombosis, and that a split-urine collection may also be very useful in the diagnostic work-up of proteinuria in adults.

Nutcracker syndrome - a mini review on current knowledge

Nutcracker syndrome (NCS) seems to be an under-diagnosed condition defined as external compression of the left renal vein and consequent blood outflow impairment. The majority of cases involve the left renal vein entrapment between abdominal aorta and the superior mesenteric artery. The exact epidemiology is unknown due to lack of consensus on diagnostic criteria and often asymptomatic courses. NCS may occur at any age with peak presentation in the second and third decade of life. There is a slight prevalence in females. The most frequent presentations include micro and macroscopic hematuria, orthostatic proteinuria, orthostatic hypotension, flank pain. Patients may develop pelvic congestion syndrome comprising dyspareunia, dysmenorrhea, abdominal pain, pelvic, gluteal, vulvar varicose veins and varicocele in men. Clinical suspicion of NCS based on signs and symptoms, requires imaging confirmation utilising modalities such as doppler ultrasonography, computed tomography and magnetic resonance angiography, intravascular ultrasound and phlebography. Treatment options of NCS range from conservative surveillance to nephrectomy, thus appropriate approach should be based on clinical manifestation and severity of symptoms. Patients presenting with mild to moderate haematuria, and acceptable symptoms should be treated conservatively. In cases of severe symptoms or when conservative management fails, invasive treatment should be considered. Recommended open surgical procedures include left renal vein distal transposition and renal autotransplantation. Endovascular stenting approach seems to be an encouraging solution. Further long term follow-up is required to create objective treatment guidelines.

Determination of prevalence of asymptomatic proteinuria and haematuria in 5-15 year aged school children in southern India

Background: Chronic renal diseases remain major cause of morbidity and mortality in young children. Although idiopathic nephrotic syndrome takes on chronic course other histopathological variants can lead to rapid progression of disease. Proteinuria in children can be physiological. Hematuria in children is always should be investigated. Persistent proteinuria in children should be investigated for any significant progressive renal disease after excluding orthostatic proteinuria. Although many countries adopt high risk screening in pediatric age group many eastern countries advocate school screening for asymptomatic proteinuria and hematuria using dipstick urine screening.Methods: A 6 month cross sectional study of asymptomatic children aged 5-15 years in metropolitan school for dipstick urine analysis for proteinuria and hematuria.Results: The ratio of male and female children in the study is 1.2:1 (total-1999, male-1056, and female-934). Age group ranged from 5 to 15 with mean 12.13 and standard deviation (SD)-2.46. Maximum number of students in the study are above 10 years of age. Children with isolated asymptomatic proteinuria have significant differences due to their sex (p value-0.005) and hematuria (p value-0.007). Prevalence of asymptomatic proteinuria is 9.8% and hematuria is 1.05%. Prevalence of persistent proteinuria is 1.35%.Conclusions: Prevalence of asymptomatic proteinuria and hematuria can be determined using dipstick urine analysis in school children. Mass screening is cost effective and feasible only if persistent cases of proteinuria are followed up, ruling out orthostatic proteinuria. Although study is feasible, it is cumbersome. High risk screening is the best cost effective method.

Our Clinical Experiences in Patients with Nutcracker Syndrome

INTRODUCTION: Nutcracker syndrome (NCS) is a rare condition caused by the compression of the left renal vein between the abdominal aorta and superior mesenteric artery. The purpose of the study was to evaluate our management of NCS. METHODS: Patients were retrospectively reviewed and sex, age, main symptoms at application, physical examination, radiological findings, laboratory examinations, and treatment were recorded. RESULTS: 23 patients (16 girls, 7 boys; age range, 5 to 16) diagnosed with NCS. Microhematuria was detected with 14 (60.8%) patients before diagnosis. And four of 9 (39.1%) were determined after diagnosis. Microhematuria was not detected in 5 (21.7%) of the patients. All patients (100%) had orthostatic proteinuria. 17 (73.9%) patients had mild, 3 (13.0%) patients had moderate and 3 (13.0%) had severe proteinuria. The mean diameter of the left renal vein (LRV) at the aortomesenteric (AM) portions and the hilar were 1.69mm±0.70 and 8.01mm±2.27. The mean angle between the superior mesenteric artery and LRV was 25.26º±7.98. DISCUSSION AND CONCLUSION: In the case of especially colic flank pain, hematuria, and proteinuria NCS should keep in mind in the differential diagnosis. Surgical management may supply more enough clinic improvement when the patient has a response to medical therapy.

Chronic Kidney Disease in Adolescents after Surgery for Congenital Heart Disease

Background: The onset of chronic kidney disease (CKD) is an important prognostic factor in young adults with congenital heart disease (CHD). Although it is likely that CKD is manifest early in CHD patients, the prevalence among adolescents is still unknown. The National Kidney Foundation’s Kidney Disease Improving Global Outcomes guidelines 2012 recommend new equations for the estimated glomerular filtration rate (eGFR) and highlight the importance of albuminuria for CKD screening. The objective of the present study was to estimate the prevalence of CKD in CHD adolescents. Methods: This observational cross-sectional study included 115 patients aged 10–18 years attending the cardiologic outpatient clinic at our institution as a follow-up after cardiac surgery in infancy related to various CHDs. CKD assessment used the CKD criteria 2012, including eGFR equations based on serum creatinine and cystatin C, and measurement of albuminuria. Results: No patient had an eGFR <60 mL min–1 1.73 m–2. However, 28.7% of all patients (95% CI 20.7–37.9) had eGFRbetween 60 and 89 mL min–1 1.73 m–2 when estimated by the bedside Schwartz creatinine-based equation,and 17.4% (95% CI 11.2–24.1) had eGFRbetween 60 and 89 mL min–1 1.73 m–2 when estimated by the Zappitelli equation, combining creatinine and cystatin C. Of all patients, 20.0% (95% CI 12.1–26.7) had orthostatic proteinuria, and none had persistent albuminuria. Conclusions: There was no evidence of CKD in the present population aged 10–18 years. The significance of an eGFR between 60 and 90 mL min–1 1.73 m–2 is not concordant for this age range and requires further investigations.