Prevalence of Inferior Vena Cava Compression in ADPKD

An unusual cause of syncope: Inferior vena cava compression by a massive renal cyst

Syncope is a commonly encountered symptom that accounts for up to 3% of all emergency department visits in the United States [1]. The differential diagnosis for patients presenting with syncope is often broad and can involve multiple distinct organ systems. This case details the hospital course of an 83-year-old male with a complicated past medical history who initially presented for syncope. Following an extensive work up it was eventually elicited that this patient had an unusual etiology of syncope, a 19 cm x 24 cm renal cyst that was compressing the inferior vena cava (IVC).

Cyst Fraction as a Biomarker in Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic kidney disease. Patients at high risk of severe disease progression should be identified early in order to intervene with supportive and therapeutic measures. However, the glomerular filtration rate (GFR) may remain within normal limits for decades until decline begins, making it a late indicator of rapid progression. Kidney volumetry is frequently used in clinical practice to allow for an assessment of disease severity. Due to limited prognostic accuracy, additional imaging markers are of high interest to improve outcome prediction in ADPKD, but data from clinical cohorts are still limited. In this study, we examined cyst fraction as one of these parameters in a cohort of 142 ADPKD patients. A subset of 61 patients received MRIs in two consecutive years to assess longitudinal changes. All MRIs were analyzed by segmentation and volumetry of the kidneys followed by determination of cyst fraction. As expected, both total kidney volume (TKV) and cyst fraction correlated with estimated GFR (eGFR), but cyst fraction showed a higher R² in a univariate linear regression. Besides, only cyst fraction remained statistically significant in a multiple linear regression including both htTKV and cyst fraction to predict eGFR. Consequently, this study underlines the potential of cyst fraction in ADPKD and encourages prospective clinical trials examining its predictive value in combination with other biomarkers to predict future eGFR decline.

Recurrent thromboses and major vessel compressions in autosomal dominant polycystic kidney disease

A 41-year-old man with autosomal dominant polycystic kidney disease (ADPKD), who had multiple previous unprovoked thrombotic events and without a known coagulopathic disorder, presented with symptomatic extensive thrombus distal to the compression site of the left common iliac vein by a dominant cyst in the left inferior renal pole. This was managed with inferior vena cava filter insertion, left nephrectomy and warfarinization. Later, there was inferior vena cava compression by the right polycystic kidney, leading to elective right nephrectomy. Post-renal transplantation, he had further episodes of partial dialysis access stenosis and extensive thromboses in the left deep and right superficial venous systems of the lower limbs despite absence of extrinsic compression. This represents the first report of recurrent mass effect and thromboembolic events in ADPKD, both before and after nephrectomy and anticoagulation. The potential increased thromboembolic risks among patients with ADPKD warrant further investigation.