Career

In 1878 he received his medical doctorate at the University of Vienna, and after graduation remained in Vienna as an assistant to Theodor Billroth (1829-1894). Later he was a professor of surgery at the Universities of Innsbruck (1894-1903) and Graz (1904-1924). Hacker is remembered for his work involving esophagoscopy, esophageal surgery and gastrointestinal surgery.

With German-American surgeon Carl Beck (1856-1911), he is credited with developing a surgical technique for balanic hypospadias.

In 1885, Hacker assisted Billroth when the latter performed the first resection of the pylorus followed by posterior gastrojejunostomy. Afterwards, Hacker documented a detailed account of the operation.

With surgeon Georg Lotheissen (1868-1941), he published two treatises concerning the esophagus, Angeborene Missbildungen, Verletzungen und Erkrankungen der Speiseröhre (Congenital abnormalities, injuries and diseases of the esophagus) and Chirurgie der Speiseröhre (Surgery of the esophagus).