Digital Public Defence: Davit L. Aghayan

MD Davit L. Aghayan at Institute of Clinical Medicine will be defending the thesis Laparoscopic parenchyma-sparing surgery in the treatment of colorectal liver metastases for the degree of PhD (Philosophiae Doctor).

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Photo: Amalie Huth Hovland, UiO

The public defence will be held as a video conference over Zoom.

The defence will follow regular procedure as far as possible, hence it will be open to the public and the audience can ask ex auditorio questions when invited to do so.

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Adjudication committee

  • First opponent: Senior Consultant Ernesto Sparrelid, Karolinska Institutet, Stockholm, Sweden
  • Second opponent: Senior Consultant Mikhail Efanov, Moscow Clinical Scientific Centre, Russia
  • Third member and chair of the evaluation committee: Professor II Heidi Beate Eggesbø, Institte of Clinical Medicine, University of Oslo

Chair of defence

Professor II Tor Inge Tønnessen, Institute of Clinical Medicine, University of Oslo

Principal Supervisor

Adjunct Professor Bjørn von Gohren Edwin, Institute of Clinical Medicine, University of Oslo


Colorectal cancer is one of the most common cancers in the Western World. Over half of the patients develop tumor spread to the liver (liver metastases) and surgery (liver resection) is the only potentially curative treatment for these patients. Traditionally, open surgery has been considered the only possible surgical approach, and anatomical resections (mostly formal hepatectomies: removal of the half part of the liver) had been accepted as a gold standard. 
Parenchyma-sparing approach targeting only the metastasis is balanced by two objectives: achieving complete tumor resection with negative margins (1), sparing as much healthy liver tissue as possible (2). It has shown its advantages over formal liver resections. 

With the development of minimally invasive techniques, laparoscopic (keyhole) approach to remove liver tumors has become a preferable alternative to open surgery. Despite that laparoscopic approach has been adopted by many specialized centres, there is a lack of sufficient evidence on laparoscopic liver surgery. 

This thesis aimed to investigate the role of laparoscopic parenchyma-sparing surgery in the treatment of colorectal liver metastases by highlighting its surgical and oncologic results, and comparing with conventional open approach in a randomized controlled trial.

Laparoscopic parenchyma-sparing resection in patients with colorectal liver metastases was associated with satisfactory surgical and oncological outcomes, also in patients with multiple metastases. Laparoscopic resection in the postero-superior (“difficult”) liver segments is a rational alternative to open approach providing shorter hospital stay, enhanced recovery and better health-related quality of life. In a randomized setting, laparoscopic approach was shown to be as good as open approach in terms of long-term oncologic outcomes.

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Published Nov. 30, 2020 2:29 PM - Last modified Dec. 15, 2020 10:47 AM