Bleeding

Before modern surgical developments, there was a very real threat that a patient would bleed to death before treatment, or during the operation. Cauterization (fusing a wound closed with extreme heat) was successful but limited - it was destructive, painful and in the long term had very poor outcomes. Ligatures, or material used to tie off severed blood vessels, are believed to have originated with Abu al-Qasim al-Zahrawi (Abulcasis)[7] in the 10th century and improved by Ambroise Paré in the 16th century. Though this method was a significant improvement over the method of cauterization, it was still dangerous until infection risk was brought under control - at the time of its discovery, the concept of infection was not fully understood. Finally, early 20th century research into blood groups allowed the first effective blood transfusions.