Supernumerary Left Renal Vein and an Implication of Secondary Renal Hypertension

Nova Southeastern University, Davie, Florida, USA

Supernumerary Left Renal Vein and an Implication of Secondary Renal Hypertension Brooke Alexander OMS-II, Nicholas Lampasona OMS-II, Taylor Mazzei OMS-II, Michael Downing OMS-II, Nicholas Lutfi, M.D., College of Osteopathic Medicine Introduction. This case study draws conclusions regarding the history of hypertension and cerebrovascular accident in a cadaveric specimen with a supernumerary, or additional, renal vein as a contributing factor. There has not been extensive investigation into the contributory mechanisms of a supernumerary renal vein and its associations with hypertension. Case Presentation. Through dissection, this 96-year-old female cadaver was found to have a supernumerary left renal vein. The patient’s medical history and cause of death included hypertension as well as a cerebrovascular accident. The patient had no other identifying factors that could be associated with persistent hypertension. Deviation From the Expected. Studies have suggested a prevalence of a supernumerary left renal vein being as little as 3.6% as compared to a supernumerary right renal vein which is much more prevalent at 32.67% (Gupta 2011). Discussion. Due to an additional renal vein in parallel and a lower venous resistance, there is an increased flow to the kidney. Thus, the arterioles of the kidney will vasoconstrict through autoregulation, leading to an increase in arteriole resistance. The result is a left renal system with a higher arteriole resistance and lower venous resistance. However, a higher ratio of arterial resistance to venous resistance, and a decrease in capillary pressure, results in the activation of the Renin-Angiotensin-Aldosterone System, possibly causing secondary renal hypertension. Conclusion. Being aware of this anomaly may help guide physicians towards individualized patient treatment rather than routine pharmaceutical management of hypertension. Identifying such anomalies could also help guide retroperitoneal surgical planning.