KILT Syndrome: A Systematic and Historical Review

Abstract

Background: Kidney and IVC Abnormalities with Leg Thrombosis (KILT) is a rare condition that affects young individuals. It involves a clinical triad that consists of deep vein thrombosis of the legs, usually caused by a congenital abnormality of the inferior vena cava (IVC) that, in turns, leads to venous stasis, with the third component, also incidental, being the presence of unilateral renal agenesis. Aims: A systematic review is conducted of the literature to understand the syndrome’s current state from the following perspectives: a) clinical (presentation, diagnosis, and treatment), b) historical (before-and-after of the KILT acronym), and c) critical (evaluation of the syndrome’s three components). Methods: A systematic review using PRISMA methodology to identify the observational studies published in PubMed/Medline and Wiley/Cochrane Library that describe cases of KILT syndrome. The search concluded on December 15, 2023. Results: The search produced 620 potential publications. Following the removal of duplicates, non-relevant studies, and appropriate screening, the final sample consisted of 27 studies covering 29 cases of KILT (19 males, eight females, and four non-defined, aged 29.8 ± 2.7 years at the time of the diagnosis). A descriptive analysis of their characteristics is provided. Conclusions: KILT syndrome is an uncommon disorder, and the conclusions are based on a limited literature sample. Most of the cases share the symptoms of painful edema on the legs, the iliac location of the thrombosis, and the incidental diagnosis of full or partial agenesis of the IVC (with the appearance of collateral venous pathways) and renal hypoplasia with hypertrophy of the contralateral kidney. The diagnosis is based on imaging scans, and the long-term use of anticoagulants is the main form of treatment. The dearth of case studies limits a more precise understanding of recurrent thrombotic episodes and the post-thrombotic syndrome.