Bochdalek hernias associated with intrathoracic kidney: A case report and systematic review of outcomes including renal function

Background: An intrathoracic kidney is a very rare form of ectopic kidney. Though increasingly recognized in the literature, impact on renal function is less well described. We report the case of a 67-year-old South Asian gentleman who presented with intrathoracic kidney and chronic kidney disease. We carried out a systematic review of the available literature on intrathoracic kidney, in order to characterize the typical clinical features, and describe likely clinical course and possible renal and extra-renal complications associated with this form of ectopia. Materials and methods: A structured search using PubMed identified all relevant published case reports from 1988 to 2018, with search restricted to papers in English, and to adult cases only (> 18 years of age). 124 records were identified, and after screening for eligibility, 34 case reports were analyzed. Results: Median age was 53.5 years, with no gender predominance. 68% (27/34) of cases were symptomatic. 29% (10/34) had a significant complication associated with their intrathoracic kidney, with 3 cases with either documented chronic or end-stage kidney disease. 26% (9/34) required surgical intervention. Conclusion: Though previously regarded as a benign entity, results from our systematic review, bearing in mind susceptibility to publication bias, suggests an appreciable risk of symptoms, complications, and in the minority a risk to kidney function. We recommend close biochemical and imaging surveillance of affected patients, with low threshold for intervention in those with renovascular stenosis, reflux, or hydronephrosis.