Post Approval Study of Liposorber LA-15 System for the Treatment of Focal Segmental Glomerulosclerosis in Children

Inclusion Criteria: * A pediatric patient is deemed suitable for inclusion in the study if the patient has FSGS with a GFR ≥ 45 ml/min/1.73 m 2 and any of the following: * Refractory nephrotic syndrome in which standard treatment options are unsuccessful (i.e., patient is unresponsive to standard corticosteroid and/or calcineurin inhibitor therapy for at least 8 weeks resulting in failure to achieve complete or partial remission); * Refractory nephrotic syndrome in which standard treatment options are not well tolerated (i.e., patients intolerant to standard therapies due to severe side effects that negatively affect quality of life without providing an acceptable level of clinical benefit); * Refractory or recurrent nephrotic syndrome in which standard therapy is contraindicated. or \- Pediatric post renal transplant patients with nephrotic syndrome associated with primary FSGS. Exclusion Criteria: * General Exclusion Criteria * Patient is greater than 21 years of age * Parent or patient is unwilling or unable to sign and date the informed consent (Note: Only patients 18-21 years of age may sign the informed consent on their own behalf) * Pregnant, lactating, or planning to become pregnant prior to completing the study (Note: The safety of the use of Liposorber® in pregnant women has not been studied. There may be unknown risks to an embryo/fetus. Sexually active women of child bearing potential should avoid pregnancy during the use of the Liposorber devic…