Multicenter trial APPAC led from the Turku University Hospital shows:

Surgery no longer needed: Thousands of patients with appendicitis may be cured with antibiotics

For more than a century, appendectomy (removal of the inflamed appendix) has been standard treatment for appendicitis, since it has been assumed that an inflamed appendix will always become perforated. A study conducted by the Turku University Hospital in the city of Turku, Finland, shows that up to 3000 appendectomies could be avoided by using antibiotics each year in Finland.

These internationally pioneering results were published in the highly rated medical journal JAMA (Journal of the American Medical Association) on June 16, 2015.

A patient with an inflamed appendix (appendicitis) does not always require immediate surgery. There are two types of appendicitis: complicated and uncomplicated. Complicated appendicitis requires always surgery, because this type will lead to perforation of the appendix. Uncomplicated appendicitis is a milder form of appendicitis and may often be cured without surgery. It is estimated that the uncomplicated form of appendicitis is much more common (80%) than the complicated form which requires immediate operation (20%). Although the operation to remove an inflamed appendix (appendectomy) is usually well tolerated, it is, nevertheless, surgery which always carries a risk of problems during or after the operation.

– Our hypothesis was that most of the patients with uncomplicated appendicitis may be treated with antibiotics rather than surgery. In this way, unnecessary operations and the morbidity associated with surgery could be avoided. At the same time, substantial savings would be made, says the main investigator of the study, Dr. PaulinaSalminen, Adjunct Professor and Head Physician of the Unit of Emergency Surgery of the Turku University Hospital.

A total of 530 patients were enrolled into to APPAC (APPendicitis ACuta) trial from November, 2009, to June, 2012. Patients diagnosed with uncomplicated appendicitis by computer tomography (CT) were enrolled, provided there were no signs of a faecalith (faecal stone blocking the appendix), perforation, pus formation (abscess) or tumour in the CT-image. 

– Patients were followed up for one year, and approximately 73 per cent of the patients treated with antibiotics never required surgery. In some cases antibiotic treatment failed and for some patients the appendicitis recurred. What is important, however, is that these patients had no more complications than conventionally treated patients. Treating these patients with antibiotics first line is safe treatment, Dr. Salminen sums up.

In the future, CT imaging will become more common for patients who attend for emergency care because of a suspicion of appendicitis. This will improve diagnostic precision and guide treatment. CT is a very reliable method for establishing whether the patient has appendicitis or not. In the future, low-dose CT-imaging will be used to minimize radiation exposure.

– Our study implies that up to 3000 appendectomies could be avoided each year in Finland. The precise health-economic consequences of these findings need to be followed up and we intend to report these later, Dr. Salminen explains.


The APPAC trial is a national, randomized multicenter trial to compare surgical treatment of uncomplicated appendicitis with antibiotic treatment. Six Finnish hospitals participated in the trial: Turku University Hospital, Oulu University Hospital, Tampere University Hospital, Mikkeli Central Hospital, Central Finland Central Hospital in Jyväskylä and Southern Osthrobothnia Central Hospital in Seinäjoki.

The Turku University Hospital has provided a state-funded grant for the study.


JAMA 2015; 313(23):2340-2348. doi:10.1001/jama.2015.6154

Antibiotic Therapy vs Appendectomy for Treatment of Uncomplicated Acute Appendicitis: the APPAC Randomized Clinical Trial.

Paulina Salminen, M.D., Ph.D., Hannu Paajanen, M.D., Ph.D., Tero Rautio, M.D., Ph.D., Pia Nordström, M.D., Ph.D., Markku Aarnio, M.D., Ph.D., Tuomo Rantanen, M.D., Ph.D., Risto Tuominen, M.P.H., Ph.D., Saija Hurme, M.Sc., Johanna Virtanen, M.D., Jukka-Pekka Mecklin, M.D., Ph.D., Juhani Sand, M.D., Ph.D., Airi Jartti, M.D., Irina Rinta-Kiikka, M.D., Ph.D., and Juha M. Grönroos, M.D., Ph.D.

The main investigator and responsible physician of the study is Dr. Paulina Salminen, Adjunct Professor.  She is the Head Physician of the Unit of Emergency Surgery of the Tyks University Hospital. Professor Juha Grönroos, Tyks Central Hospital, and Professor Hannu Paajanen, University of Eastern Finland, have also functioned as responsible physicians for the trial.   

The other members of the study team are:  Tero Rautio, M.D., Ph.D. (Oulu), Pia Nordström, Adjunct Professor (Tampere), Markku Aarnio, Adjunct Professor (Jyväskylä), Tuomo Rantanen, Adjunct Professor (Seinäjoki), Juhani Sand, Adjunct Professor (Tampere), Jukka-Pekka Mecklin, Professor (Jyväskylä), Airi Jartti, M.D., Adjunct Professor (Oulu), Risto Tuominen, Professor, (Turku University), Saija Hurme, biostatistician (Turku University), Johanna Virtanen, M.D., specialist physician (Turku) and Irina Rinta-Kiikka, M.D., Ph. D. (Tampere).

JAMA Editorial: Treating Appendicitis Without Surgery


See more photos.

Photographer: Henry Suhonen

For further information, please contact:

  • Paulina Salminen, Adjunct Professor, Head of Department of Emergency Surgery, Tyks University Hospital



This release has been compiled by Tuula Vainikainen, editor and science editor, science communication consultant for the Hospital District of Southwest Finland. Ms. Vainikainen can be reached by email tuula.vainikainen(a)

Modified : 19/08/2021 08:50
Created : 16/06/2015 12:37