Studies on acute appendicitis with a special reference to appendicoliths and periappendicular abscesses

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

Auditorium 1 of Oulu University Hospital, Kajaanintie 50

Topic of the dissertation

Studies on acute appendicitis with a special reference to appendicoliths and periappendicular abscesses

Doctoral candidate

Licenciate in medicine, consultant surgeon in gastroenterological surgery Jari Mällinen

Faculty and unit

University of Oulu Graduate School, Faculty of Medicine, Medical Research Center

Subject of study



Professor Pauli Puolakkainen, Helsinki University Central Hospital /Helsinki University


Professor Jyrki Mäkelä, Oulu University/ Oulu University Hospital

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More information about acute appendicitis

It is now known, that acute appendicitis does not inevitably lead to appendiceal perforation without surgical treatment. Most cases are uncomplicated by nature and can often be treated with antibiotics without operation. On the other hand, complicated acute appendicitis with appendiceal perforation usually requires operative treatment. This supports the importance of accurate differential diagnosis between uncomplicated and complicated acute appendicitis to enable correct treatment. According to the thesis, this differentiation can not be done reliably enough without modern imaging such as computed tomography.

An appendicolith is a calcified deposit of faecal material in the appendiceal lumen. It's presence is known to predict perforation and failure of conservative treatment. However, acute appendicitis presenting with an appendicolith is not officially classified as complicated appendicitis. In this thesis, clear histopathological differencies were detected between acute uncomplicated appendicitis and acute appendicitis without perforation, but presenting with an appendicolith. This supports the hypothesis of the potentially complicated nature of appendicolith appendicitis.

Appendiceal perforation can lead to generalized peritonitis or an encapsulated periappendicular abscess. An abscess can usually be treated in the acute phase with antibiotics without surgery. The thesis aimed to determine the need of an interval appendectomy after initial treatment after the infection has subsided. An unexpectedly high rate of appendiceal neoplasms was detected in the study population. All the neoplasms were detected in patients over 40 years of age. This supports the need of an interval appendectomy in this age group.
Last updated: 1.3.2023