Eponymously named for its depiction in anatomical illustrations by the Italian baroque artist Pietro Berrettini da Cortona (1596/97-1699) the Berrettini anastomosis is a communicating branch between the median and ulnar common digital nerves in the palmar aspect of the hand. With a reported prevalence varying in the literature between 4% and 94% there is debate whether it should be considered part of normal anatomy or an anatomical variant. Thought from cadaveric studies to be a purely sensory nerve, injury of the Berrettini anastomosis can alter sensation in the third and fourth digits of the hand. Studies published in 2020 found that stimulating the ulnar nerve produced recordable SNAPs in from the third digit in about one third of patients; and that it is also possible to have an ulnar nerve sensory contribution to innervation of the second digit.

After noticing a discrepancy between the date given for the discovery of the Berrettini anastomosis and the lifetime of Pietro Berrettini da Cortona I researched the surviving original sources and their secondary literature.

Despite being named after Berrettini who died in 1699 the date of its discovery has been widely reported in the medical literature as 1741, the date of the publication of engravings of his drawings in the illustrated anatomical textbook Tabulae anatomicae a celeberrimo pictore Petro Berrettino Cortonensi delineatae rather than when they were created. The anatomical drawings, which are vividly posed and highlight the anatomy of nervous system, survive in the special collections of the University of Glasgow, and are thought to have been prepared from dissections made at the Santo Spirito Hospital in Rome, probably in 1618. As this is the first known depiction of the Berrettini anastomosis the date given in the medical literature should reflect this rather than a date long after the eponymous Berrettini's death.