title: Anatomical Variations of Upper Segmental Renal Artery and Clinical Significance.
abstract: BACKGROUND
  Classically each kidney is supplied by a single renal artery. In its course renal artery divides into anterior and posterior division, both of these division further divide into segmental arteries that are apical, upper, middle, lower and posterior. Segmental arteries are representing an end artery and they form independent renal segments. In their course they are closely related with collecting system. So, a thorough in depth knowledge of the variations in segmental arteries is a basic requirement for surgeons.
  
  
  OBJECTIVE
  To observe and investigate the anatomical variations in arterial pattern of upper segmental renal artery and its relations with collecting system of ducts in human kidneys.
  
  
  METHODS
  Fifty human kidneys of both sexes were observed and studied by corrosion cast method. Different colour coded cast material (butyl butyrate) like red for artery and black for collecting ducts were used. 20% solution of butyl butyrate in acetone was injected into renal artery and ureter of the kidneys. After polymerization (24 hours) these kidneys were kept immersed in a bath of concentrated KOH solution at 50(0)C for 24-48 hours for corrosion to obtain the endocasts. These endocasts were cleaned and washed under running tap water and photographed.
  
  
  RESULTS
  In present study upper segmental artery was found in 49 (98%) kidneys. It was absent in 1 (2%) kidney. We observed four types of variations in arterial pattern of upper segmental artery namely Upper Segmental Artery Type-1 (USAT1), Upper Segmental Artery Type-2 (USAT2), Upper Segmental Artery Type-3 (USAT3), Upper Segmental Artery Type-4 (USAT4) and they were found in 20 (40%), 14 (28%), 10 (20%), 5 (10%) kidneys respectively. We also observed two different variations in the anatomical relations between upper segmental artery and collecting system namely Upper Segmental Artery Group -1 (USAG1) and Upper Segmental Artery Group-2 (USAG2). USAG1 was found in 40 (80%) kidneys and USAG2 in 9 (18%) kidneys respectively.
  
  
  CONCLUSIONS
  Anatomical knowledge of these variations is very important and useful for the uro-surgeons for best outcome and minimal complications in and during nephrectomies, removal of calculi, surgery of renal tumors or other various intrarenal surgeries.
authors.affiliation: Associate Professor, Department of Anatomy, Career Institute of Medical Sciences and Hospitals , Lucknow, India .
authors.forename: Gyan Prakash
authors.initials: GP
authors.lastname: Mishra
authors.affiliation: Professor, Department of Anatomy, Career Institute of Medical Sciences and Hospitals , Lucknow, India .
authors.forename: Shobha
authors.initials: S
authors.lastname: Bhatnagar
authors.affiliation: Additional Professor, Department of Anatomy, Aiims , Jodhpur, India .
authors.forename: Brijendra
authors.initials: B
authors.lastname: Singh
keywords: Collecting System; Corrosion cast; Intrarenal surgeries; Kidney