Plasma α-Glutathione S-Transferase in Patients with Chronic Mesenteric Ischemia and Median Arcuate Ligament Syndrome.

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.

Early Identification of Chronic Mesenteric Ischemia with Endoscopic Duplex Ultrasound.

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.

Laparoscopic Surgery for Median Arcuate Ligament Syndrome (MALS): A Prospective Cohort of 52 Patients.

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.

Laser Doppler Flowmetry and Visible Light Spectroscopy of the Gastric Tube During Minimally Invasive Esophagectomy.

INTRODUCTION: Ischemia is considered as the main reason for thoracic gastroesophageal anastomotic leaks after esophagectomy. Microcirculatory monitoring with laser Doppler flowmetry and visible light spectroscopy may provide valuable intraoperative real-time information about the gastric tube's tissue perfusion and circulation. PATIENTS AND METHODS: Ten patients with esophageal cancer operated with minimally invasive esophagectomy participated in this single-center, prospective, observational pilot study. A single probe with laser Doppler flowmetry and visible light spectroscopy was used to perform transserosal microcirculation assessment of the gastric tube at predefined anatomical sites during different operation phases. Group comparison and changes were evaluated using the paired sample t-test. RESULTS: A reduction in StO2 was found at all measuring sites after the gastric tube formation compared with the baseline measurements. The mean StO2 reduction from baseline to gastric tube formation and after anastomosis was 16% (range 4%-28%) and 42% (range, 35%-52%), respectively. A statistically significant increase in the rHb concentration, representing venous congestion, was detected at the most cranial part of the gastric tube (P = 0.04). Three patients developed anastomotic leaks. CONCLUSION: Intraoperative real-time laser Doppler flowmetry and visible light spectroscopy are feasible and may provide insight to microcirculatory changes in the gastric tube and at the anastomotic site. Patients with anastomotic leaks seem to have critical local tissue StO2 reduction and venous congestion that should be further evaluated in studies with larger sample sizes.

Perioperative Microcirculatory Changes Detected with Gastroscopy Assisted Laser Doppler Flowmetry and Visible Light Spectroscopy in Patients with Median Arcuate Ligament Syndrome.

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.

Gastroscopy assisted laser Doppler flowmetry and visible light spectroscopy in patients with chronic mesenteric ischemia.

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.