Simen Tveten Berge

• Mathisen, Sven Ross & Berge, Simen Tveten (2026). A seven-year single-center experience with large-bore percutaneous closure in endovascular aneurysm repair. Vascular. ISSN 1708-5381. doi: 10.1177/17085381261429288. Fulltekst i vitenarkiv
• Mathisen, Sven Ross & Berge, Simen Tveten (2025). Open Surgical Conversion After Failed Endovascular Aneurysm Sealing. Vascular Health and Risk Management. ISSN 1176-6344. Volume 21, s. 477–488. doi: 10.2147/vhrm.s513365. Fulltekst i vitenarkiv Vis sammendrag

  Objective: The aim of this study was to investigate the early and late outcomes of Open Surgical Conversion (OSC) following the failure of Endovascular Aneurysm Sealing (EVAS) endografts, regarding surgical technique, morbidity and mortality. Method and material: A single center retrospective observational cohort of 46 patients undergoing OSC after EVAS failure. Primary endpoints were primary technical procedural success and 30-day mortality. Secondary endpoints were complications and primary prosthesis patency. Results: Primary technical procedural success was 97.8% (45/46). Elective 30-day mortality for OSC was 10.9% (5/42) and 75% (3/4) for acute OSC procedures. Median survival after OSC was 4.2 years (IQR 1.0, 4.9 years). Four peri-operative and 17 post-operative complications were registered. Major complications included bleeding, myocardial infraction, acute renal failure and splenectomy. Primary prosthesis patency was 82.6% (38/46) at 30-days. At median follow-up of 4.7 years (IQR 3.9, 5.3 years) 69.6% (32/46) of the patients are still alive with patent vascular prostheses. Conclusion: Open surgical conversion achieved acceptable technical success rate for failed EVAS, with better outcomes in elective versus emergency procedures. Enhanced surveillance with timely interventions before rupture and careful patient selection through multidisciplinary evaluation are essential for optimizing surgical outcomes.

• Berge, Simen Tveten; Naletov, Konstantin & Mathisen, Sven Ross (2025). Long Term Follow Up of Abdominal Aortic Aneurysms Treated With Endovascular Aneurysm Sealing (EVAS) and Endovascular Aneurysm Repair (EVAR): A Single Centre Retrospective Cohort. EJVES Vascular Forum (EJVES VF). 64, s. 50–56. doi: 10.1016/j.ejvsvf.2025.05.003. Fulltekst i vitenarkiv Vis sammendrag

  Objective: The Nellix endovascular aneurysm sealing (EVAS) system demonstrated promising short and midterm outcomes following its introduction in 2011. However, long term results have shown a high incidence of graft failure. This study aimed to compare the long term outcomes of EVAS compared with standard endovascular aneurysm repair (EVAR). Methods: This single centre, retrospective, comparative cohort analysis used prospectively registered data from an internal quality control registry at Innlandet Hospital Trust, Hamar Hospital, Norway. Two hundred and eighty-one patients underwent elective endovascular repair for aorto-iliac aneurysm disease between 2013 - 2016. Primary elective EVAR (n = 164) was compared with primary elective EVAS (n = 117). Results: Technical success was achieved in 100% of the EVAR and EVAS cases. The EVAS patients had a shorter hospital stay (3.7 vs. 4.7 days; p = 0.008), and lower post-procedural C reactive protein (CRP) levels (p < 0.001). No statistically significant differences were found in 30 day (p = 0.79), one year (p = 0.97), or long term all cause mortality rates, with a median follow up of 9.3 years (p = 0.93). During long term follow up, type II endoleaks were significantly less common in EVAS patients (2.6% vs. 32.3%; p < 0.001). However, EVAS had lower device durability, with freedom from device failure at five years of 54% compared with 98% for EVAR (p < 0.001). Open surgical conversion was required in 31% of EVAS patients and 2.4% of EVAR patients (p < 0.001). Aneurysm sac growth ≥5 mm was recorded in 47% of EVAS cases compared with 17.1% of EVAR cases (p < 0.001). Conclusion: While long term all cause mortality was comparable between EVAS and EVAR, EVAS was associated with statistically significantly higher rates of graft failure, aneurysm sac growth, aneurysm related death, and open surgical conversion. Close monitoring of new prosthetic devices in registries is essential to identify early signs of device failure.

• Mathisen, Sven Ross & Berge, Simen Tveten (2024). A Single Centre Long Term Follow Up of the Nellix Endovascular Aneurysm Sealing System. European Journal of Vascular and Endovascular Surgery. ISSN 1078-5884. 67(5), s. 747–753. doi: 10.1016/j.ejvs.2023.11.010. Fulltekst i vitenarkiv
• Kazmi, Syed Sajid Hussain; Safi, Natkai; Berge, Simen Tveten; Kazmi, Marryam; Sundhagen, Jon Otto & Hisdal, Jonny (2022). Laparoscopic Surgery for Median Arcuate Ligament Syndrome (MALS): A Prospective Cohort of 52 Patients. Vascular Health and Risk Management. ISSN 1176-6344. 18, s. 139–151. doi: 10.2147/VHRM.S350841. Fulltekst i vitenarkiv Vis sammendrag

  Background: The selection of patients with MALS for surgical treatment depends upon the reliability of the symptom interpretation and the diagnostic work-up. We aimed to follow up the results of the laparoscopic decompression of the patients with MALS. Patients and Methods: In a single-center, 52 consecutive MALS patients were followed-up, prospectively, after transperitoneal laparoscopic decompression. MALS was diagnosed with a computed tomography angiography (CTA) verified stenosis, ≥ 50% of the celiac artery (CA), and with duplex ultrasound, a peak systolic velocity (PSV) ≥ 2.0 m/s. Postoperative, CTA, and duplex ultrasound were performed, and the patients were followed-up at 3, 6, 12 months, and yearly after that. Results: Mean age of the patients was 47 ± 21 years, and 65% were females. The patients had a mean weight loss of 8.4 ± 7.2 kg. Fifty-one patients had the laparoscopic operation with a mean operation time of 102 ± 28 minutes. Forty-seven patients (90%) achieved relief from the symptoms either completely (67%) or partially (23%) at 3– 6 months of follow-up. Significant improvement in postoperative PSV was found compared to the preoperative values, p< 0.001. Five patients (10%) with no immediate effect of the operation, but two of them became free from symptoms during the mean study follow-up of 2.4 ± 2 years. Five patients (10%) had operative complications, including one trocar injury to the liver, one pneumothorax, and three cases of bleeding from the branches of CA. Two patients died of cancer disease during the study period. Only two patients (4%) had symptoms relapse, both later treated successfully. Conclusion: Laparoscopic transperitoneal decompression provides most of the patients a persistent relief from MALS symptoms. Keywords: median arcuate ligament syndrome, postprandial pain, laparoscopy, mesenteric ischemia

• Kazmi, Syed Sajid Hussain; Safi, Natkai; Berge, Simen Tveten; Kazmi, Marryam; Sundhagen, Jon Otto & Julien, Kari [Vis alle 10 forfattere av denne artikkelen] (2022). Plasma α-Glutathione S-Transferase in Patients with Chronic Mesenteric Ischemia and Median Arcuate Ligament Syndrome. Vascular Health and Risk Management. ISSN 1176-6344. 18, s. 567–574. doi: 10.2147/VHRM.S365625. Fulltekst i vitenarkiv Vis sammendrag

  Background: Chronic mesenteric ischemia (CMI) due to either atherosclerosis of the mesenteric arteries or median arcuate ligament syndrome (MALS) is an underdiagnosed entity. The etiology of MALS and its existence have been debated and questioned. We aimed to identify plasma biomarkers indicating mesenteric ischemia in patients with CMI and MALS. Methods: Plasma α-glutathione S-transferase (α-GST), intestinal fatty acid-binding protein (I-FABP), citrulline, and ischemia modified albumin (IMA) were analyzed in fifty-eight patients with CMI (Group A, n=44) and MALS (Group B, n=14) before and after revascularization. The plasma levels of these potential biomarkers were compared with those of healthy individuals (Group C, n=16). Group comparison was performed with the Mann–Whitney U-test. Cross-tabulation and its derivatives were obtained. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were calculated. Results: Plasma levels of α-GST were significantly raised in the patients with CMI (7.8 ng/mL, p< 0.001) and MALS (8.4 ng/mL, p< 0.001), as compared with the control Group C (3.3 ng/mL). The threshold for normal median plasma α-GST levels of 4 ng/mL yielded a sensitivity of 93% and 86%, specificity of 86% and 88%, respectively, for the diagnosis of CMI due to atherosclerosis and MALS. AUC of ROC curves was 0.96 (p< 0.0001) for CMI and 0.85 (p< 0.002) for MALS. The patient groups did not differ from the healthy controls in any other biomarkers. Conclusion: Plasma α-GST levels are elevated in CMI and MALS patients. Elevated plasma levels of α-GST suggest ischemia as the etiology of MALS.

• Safi, Natkai; Ånonsen, Kim Vidar; Berge, Simen Tveten; Medhus, Asle Wilhelm; Sundhagen, Jon Otto & Hisdal, Jonny [Vis alle 7 forfattere av denne artikkelen] (2022). Early Identification of Chronic Mesenteric Ischemia with Endoscopic Duplex Ultrasound. Vascular Health and Risk Management. ISSN 1176-6344. s. 233–243. doi: 10.2147/VHRM.S358570. Fulltekst i vitenarkiv Vis sammendrag

  Introduction: Due to diagnostic delay, chronic mesenteric ischemia (CMI) is underdiagnosed. We assumed that the patients suspected of CMI of the atherosclerotic origin or median arcuate ligament syndrome (MALS) could be identified earlier with endoscopic duplex ultrasound (E-DUS). Patients and Methods: Fifty CMI patients with CTA-verified stenosis of either ≥ 50% and ≥ 70% of celiac artery (CA) and superior mesenteric artery (SMA) were examined with E-DUS and transabdominal duplex ultrasound (TA-DUS). Peak systolic velocities (PSV) of ≥ 200cm/s and ≥ 275cm/s for CA and SMA, respectively, were compared with CTA. Subgroup analysis was performed for the patients with (n=21) and without (n=29) prior revascularization treatment of CMI. The diagnostic ability of E-DUS and TA-DUS was tested with crosstabulation analysis. Receiver operating characteristics (ROC) curve analysis was performed, and the area under the curve (AUC) was calculated to investigate the test accuracy. Results: In the patients with ≥ 70% stenosis, E-DUS had higher sensitivity than TA-DUS (91% vs 81% for CA and 100% vs 92% for SMA). AUC for SMA ≥ 70% in E-DUS was 0.75 and with TA-DUS 0.68. The sensitivity of E-DUS for CTA-verified stenosis ≥ 70% for CA was 100% in the patients without prior treatment. E-DUS demonstrated higher sensitivity than TA-DUS for both arteries with stenosis ≥ 50% and ≥ 70% in the treatment-naive patients. Conclusion: E-DUS is equally valid as TA-DUS for the investigation of CMI patients and should be used as an initial diagnostic tool for patients suspected of CMI.

• Berge, Simen Tveten; Safi, Nathkai; Medhus, Asle Wilhelm; Sundhagen, Jon Otto; Hisdal, Jonny & Kazmi, Syed Sajid Hussain (2020). Perioperative microcirculatory changes detected with gastroscopy assisted laser doppler flowmetry and visible light spectroscopy in patients with median arcuate ligament syndrome. Vascular Health and Risk Management. ISSN 1176-6344. 16, s. 331–341. doi: 10.2147/VHRM.S252192. Fulltekst i vitenarkiv Vis sammendrag

  Purpose: Physiological tests may aid in diagnosing median arcuate ligament syndrome (MALS). MALS is a symptomatic compression of the celiac artery causing symptoms similar to chronic mesenteric ischemia (CMI) of atherosclerotic etiology. Simultaneous use of visible light spectroscopy (VLS) and laser doppler flowmetry (LDF) during upper endoscopy may detect microcirculatory changes in these patients. Patients and Methods: In a single-center, prospective comparative cohort, 25 patients were evaluated for MALS. Patients with a consensus diagnosis of MALS (n=15) underwent a gastroscopy assisted, transmucosal microcirculatory assessment with LDF and VLS. Results were compared to individuals with normal intestinal circulation (n=38) evaluated with duplex ultrasonography, and to patients with chronic mesenteric ischemia (n=32). Treatment response was evaluated clinically at 1, 3, 6, and 12 months, and with ultrasound, VLS and LDF at three months. Health-related quality of life (QoL) was assessed with Euroqol (EQ-5D-5L), preoperatively, and 12 months postoperatively. Results: Preoperative mean transmucosal oxygen saturation was significantly lower in patients with MALS (SO2 76± 6), as compared to healthy individuals (SO2 81± 4), p=0.02. An overall significant improvement in SO2 after surgical decompression of the celiac artery was found (SO2 81± 3.7, p=0.05). Eleven (92%) patients with clinical improvement after laparoscopic decompression had a definitive diagnosis of MALS. Median follow-up was 18 months (4– 24 months). Four of the five dimensions investigated with EQ-5D-5L improved. Conclusion: VLS detected a significantly lower baseline transmucosal SO2 in patients with MALS as compared to control subjects with normal intestinal circulation. An improvement in SO2 after laparoscopic decompression was found, supporting a possible ischemic etiology in our patient population.

• Kazmi, Syed Sajid Hussain; Berge, Simen Tveten; Sahba, Mehdi; Medhus, Asle Wilhelm & Sundhagen, Jon Otto (2020). A Short Series of Laparoscopic Mesenteric Bypasses for Chronic Mesenteric Ischemia. Vascular Health and Risk Management. ISSN 1176-6344. 16, s. 87–97. doi: 10.2147/VHRM.S243264. Fulltekst i vitenarkiv Vis sammendrag

  Background: Laparoscopic aortomesenteric bypass may be performed to treat the chronic mesenteric ischemia patients who are not suitable for endovascular treatment. This study presents an initial experience with a limited series of laparoscopic mesenteric artery revascularization for the treatment of mesenteric ischemia. Methods: Chronic mesenteric ischemia (CMI) patients with previous unsuccessful endovascular treatment or with arterial occlusion and extensive calcification precluding safe endovascular treatment were offered laparoscopic mesenteric revascularization. From October 2015 until November 2018, nine patients with CMI underwent laparoscopic revascularization. In addition to demographic data and perioperative results of the treatment, graft patency was assessed with Duplex ultrasound at 1, 3, 6 and 12 months, and annually thereafter. A descriptive analysis of the data was performed. Results: All bypasses were constructed with an 8 mm ring enforced expanded polytetrafluoroethylene graft in a retrograde fashion (from infrarenal aorta or iliac artery) to either superior mesenteric artery or splenic artery (2 cases). Median operation time was 356 mins (range 247– 492 mins). Five patients had a history of unsuccessful endovascular treatment. Laparoscopic technical success was 78%, and the primary open conversion rate was 22%. All laparoscopic revascularization procedures remained patent after discharge during a median follow-up time of 26 months (range 18– 49 months). The primary graft patency at 30 days was 78%. Primary assisted, and secondary graft patency was 78% and 100%, respectively. Median weight gain was 2 kg (range 2– 18 kg), and all patients achieved relief from postprandial pain and nausea. No mortality was observed during the follow-up period. Conclusion: Laparoscopic aortomesenteric revascularization procedures for chronic mesenteric ischemia are feasible but require careful patient selection. These procedures should only be performed at referral centers by vascular surgeons with prior experience in laparoscopic vascular surgery.

• Berge, Simen Tveten; Safi, Nathkai; Medhus, Asle Wilhelm; Ånonsen, Kim Vidar; Sundhagen, Jon Otto & Hisdal, Jonny [Vis alle 7 forfattere av denne artikkelen] (2019). Gastroscopy assisted laser Doppler flowmetry and visible light spectroscopy in patients with chronic mesenteric ischemia. Scandinavian Journal of Clinical and Laboratory Investigation. ISSN 0036-5513. 79(7), s. 541–549. doi: 10.1080/00365513.2019.1672084. Fulltekst i vitenarkiv Vis sammendrag

  Mucosal pathology due to chronic mesenteric ischemia (CMI) is rarely seen during upper endoscopy. Combining Laser Doppler Flowmetry (LDF) and Visible Light Spectroscopy (VLS) may aid in detection of CMI at an early stage. We aimed to investigate the utility of LDF and VLS in detecting microcirculatory changes in patients with CMI during upper endoscopy. In a single center, prospective study, 104 patients were evaluated for mesenteric ischemia during a 24 months period. Patients with a consensus diagnosis of CMI (n = 40) were examined with LDF and VLS. Thirty-two were successfully treated and had a definitive diagnosis of CMI. Results were compared with controls (n = 38) with normal intestinal circulation evaluated with duplex ultrasonography (DUS). Treatment response was evaluated clinically and with DUS at 1 month and with VLS and LDF at 3 months. A significant reduction in mucosal capillary hemoglobin oxygen saturation (SO2) was found in CMI patients compared to controls before treatment: mean ± SD: 67 ± 9%, 81 ± 4%, respectively (p < .001). A significant reduction was also seen for the relative hemoglobin (rHb) amount, flow and velocity (p < .001). The sensitivity of SO2 measured by VLS for diagnosing CMI was 94% and the specificity 72% (cut-off 78%), calculated with ROC curve analysis. A combination of SO2 and rHb increased the test sensitivity and specificity to 97% and 79%, respectively. Conclusion: CMI patients have significantly reduced microcirculation in the stomach and duodenum compared to controls. The results suggest that VLS should be included when performing an upper endoscopy in patients with suspected CMI.

• Kazmi, Syed Sajid Hussain; Krog, Anne Helene; Berge, Simen Tveten; Sundhagen, Jon Otto; Sahba, Mehdi & Falk, Ragnhild Sørum (2017). Patient-perceived health-related quality of life before and after laparoscopic aortobifemoral bypass. Vascular Health and Risk Management. ISSN 1176-6344. 13, s. 169–176. doi: 10.2147/VHRM.S134669. Fulltekst i vitenarkiv Vis sammendrag

  Background: In patients operated with laparoscopic aortobifemoral bypass (LABFB) for atherosclerotic obstruction in aortoiliac segment, the main focus of the reports published during the last two decades has been morbidity and mortality. The primary objective of this study was to examine the health-related quality of life (HRQL) in these patients before and after LABFB. Patients and methods: Fifty consecutive patients (27 females) with Trans-Atlantic Inter-Society Consensus II, type D lesions were prospectively included. Short-Form 36 (SF-36) questionnaire was used to get information about the HRQL before LABFB and at 1, 3 and 6 months after the operation. Main indication for LABFB was intermittent claudication. Linear mixed-effect models were used to assess changes in HRQL over time. Age, gender, smoking, blood loss, operation time, concomitant operation, the American Society of Anesthesiologists category, length of hospital stay, previous vascular procedures and aorta cross-clamping were used as fixed factors and their impact on the physical components of the SF-36, as well as the summary scores were determined with univariate analysis. Variables with P<0.2 were included in the multivariate regression analysis. P<0.05 was considered statistically significant. Results: Statistically significant improvement was found in all SF-36 domains as well as in the summary scores after LABFB compared to the preoperative scores. The improvement in scores was substantial already at 1 month and the effect was maintained at 3 and 6 months survey time points. Concomitant operations had a statistically significant negative impact on the physical components of SF-36. Data completeness of item questionnaires was 93% in the whole material. Reliability scale and homogeneity estimates for the eight domains had high internal consistency. Conclusion: Patients operated with LABFB for Trans-Atlantic Inter-Society Consensus II, type D lesions have reduced HRQL. LABFB leads to substantial and statistically significant improvement in the patients’ HRQL, when examined with SF-36. These results need to be replicated by a randomized clinical trial.

• Berge, Simen Tveten & Kjetland, Eyrun Flörecke (2009). Generic praziquantel in South Africa: the necessity for policy change to provide cheap, safe and effcacious schistosomiasis drugs for the poor, rural population. Southern African Journal of Infectious Diseases (SAJID). ISSN 2312-0053. doi: 10.1080/10158782.2011.11441415. Fulltekst i vitenarkiv

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