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Who made what? The Ross renal biopsy needle

The successful practice of percutaneous renal biopsy was greatly enhanced in the 1950s by Kark and Muehrcke of Chicago. Using an abdominal bolster to support the kidney, they positioned their patients in the prone instead of the sitting position and they used the Vim-Silverman biopsy needle with Franklin’s prongs. In modern practice, the yield of satisfactory biopsies has now been much increased and complication rates decreased by the use of real-time ultrasound-guided biopsy and by the use of automated biopsy needles; but no such refinements were available in the 1950s when measurements taken from abdominal radiographs, sometimes with intravenous contrast if the patient’s condition allowed, were the only assistance derived from imaging techniques. Kark and Muehrcke also used an exploring needle, which moved with respiration once inserted into the renal capsule, to localise the kidney before inserting the biopsy needle. WhenMuehrcke visited London in 1956 he taught the Chicago technique to John Ross (1920–2016), at that time a senior registrar at The London Hospital and later a physician in Hereford. Ross then taught the technique to many other physicians around Britain. The Chicago technique still carried a risk that the Franklin prongs might be pushed beyond the renal cortex and into the medulla, thereby increasing the risk of complications while providing a biopsy of little or no diagnostic value. Ross minimised this risk by designing a sliding head for the needle. The biopsy needle (C in Figure 1), with the head closed as in (B), was inserted until its point was in the kidney. Keeping the head closed, the stylet (D) was then withdrawn. While the barrel of the needle was gripped with the left hand, the Franklin prongs (E) were tapped through Figure 1. The Ross renal biopsy needle.