Digital Public Defence: Simen Tveten Berge

MD Simen Tveten Berge at Institute of Clinical Medicine will be defending the thesis “Detection of microcirculatory changes and treatment of patients with atherosclerotic chronic mesenteric ischemia and median arcuate ligament syndrome” for the degree of PhD (Philosophiae Doctor).

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Photo: Per Holland

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.

Click here to participate in the public defence

Download Zoom here

Due to copyright reasons, an electronic copy of the thesis must be ordered from the faculty. In order for the faculty to have time to process the order, it must be received by the faculty no later than 2 days prior to the public defence. Orders received later than 2 days before the defence will not be processed. Inquiries regarding the thesis after the public defence must be addressed to the candidate.

Digital Trial Lecture – time and place

See Digital Trial Lecture.

Adjudication committee

  • First opponent: Professor Stefan Acosta, Skåne University Hospital, Sweden
  • Second opponent: Professor Inge Fourneau, University of Leuven and University Hospital Leuven, Belgium
  • Third member and chair of the evaluation committee: Professor Truls Erik Bjerklund Johansen, University of Oslo

Chair of the Defence

Professor Johan Ræder, University of Oslo

Principal Supervisor

Associate Professor Syed Sajid Hussain Kazmi, University of Oslo


There is a high prevalence of atherosclerotic mesenteric artery stenosis and external compression of the celiac artery. The bowel is protected from ischemia by a redundant collateral circulation, and only a few patients become symptomatic. Left untreated, there is significant morbidity and risk of mortality. The diagnosis is challenging. A functional test to prove arterial insufficiency would aid identification of patients who would benefit from surgical revascularization. Treatment is open surgical bypass or endovascular therapy.

The aims of the thesis were to assess the utility of laser Doppler flowmetry and visible light spectroscopy (VLS) during upper endoscopy in detection of microcirculatory deficiencies in patients with chronic mesenteric ischemia (CMI) or median arcuate ligament syndrome (MALS), and to explore the feasibility of a laparoscopic mesenteric bypass in patients with CMI. 

A significantly lower oxygen saturation measured by VLS was found in both patients with CMI and MALS, as compared to controls. For diagnosing CMI, the test had a higher sensitivity and specificity than previously reported functional tests.

Whether MALS is of ischemic or neurogenic etiology is disputed. The low oxygen saturation in patients with MALS presented in this thesis suggests an ischemic etiology.

The findings suggest that VLS should be part of the diagnostic work-up of patients with CMI or MALS.

Primary and secondary graft patency of the laparoscopic mesenteric bypass was 78% and 100% respectively. The procedure may be an option for experienced laparoscopic vascular surgeons in case of lesions unsuitable for, or after failed endovascular treatment, but further studies are required to evaluate this novel approach adequately.

Additional information

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Published Feb. 4, 2022 10:04 AM - Last modified Feb. 17, 2022 12:38 PM