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.

Perioperative humoral stress response to laparoscopic versus open aortobifemoral bypass surgery.

Minimally invasive surgery seems to reduce hormonal stress response to surgery, but has not previously been examined in major abdominal vascular surgery. Aortic cross-clamping time and operation time is known to be longer in the totally laparoscopic aortobifemoral bypass (LABF) as compared to open aortobifemoral bypass (OABF). The main objective of our study was to measure the hormonal stress response during surgery and aortic cross-clamping in patients undergoing a totally laparoscopic versus an open aortobifemoral bypass. This was a sub-study of a larger randomized controlled multicentre trial. Thirty consecutive patients with severe aortoiliac occlusive disease were randomized to either a laparoscopic (LABF) or an open (OABF) procedure. The surgical stress response was measured by perioperative monitoring of adrenocorticotropic hormone (ACTH), aldosterone, metanephrine and cortisol at eight different time-points. During surgery. there was an increase in all humoral stress markers in both groups. The analysis of covariance showed increased levels of cortisol and ACTH in open group at 24 h time-point as compared to the baseline and this difference was statistically significant between the two groups, which indicate an earlier return to baseline levels in the laparoscopic group. Results from the General Estimated Equations (GEE) model indicate that LABF generates a lower level of metanephrine and higher level of aldosterone as compared to OABF. In conclusion, although they have higher levels of ACTH, aldosterone and cortisol during surgery, the patients operated with a laparoscopic aortobifemoral bypass achieve earlier hormonal homeostasis after surgery compared to open aortobifemoral bypass.

A comparative cohort study of totally laparoscopic and open aortobifemoral bypass for the treatment of advanced atherosclerosis.

BACKGROUND: Totally laparoscopic aortobifemoral bypass (LABF) procedure has been shown to be feasible for the treatment of advanced aortoiliac occlusive disease (AIOD). This study compares the LABF with the open aortobifemoral bypass (OABF) operation. METHODS: In this prospective comparative cohort study, 50 consecutive patients with type D atherosclerotic lesions in the aortoiliac segment were treated with an LABF operation. The group was compared with 30 patients who were operated on with the OABF procedure for the same disease and time period. We had an explanatory strategy, and our research hypothesis was to compare the two surgical procedures based on a composite event (all-cause mortality, graft occlusion, and systemic morbidity). Stratification analysis was performed by using the Mantel-Haenszel method with the patient-time model. Cox multivariate regression method was used to adjust for confounding effect after considering the proportional hazard assumption. Cox proportional cause-specific hazard regression model was used for competing risk endpoint. RESULTS: There was a higher frequency of comorbidity in the OABF group. A significant reduction of composite event, 82% (hazard ratio 0.18; 95% CI 0.08-0.42, P=0.0001) was found in the LABF group when compared with OABF group, during a median follow-up time period of 4.12 years (range from 1 day to 9.32 years). In addition, less operative bleeding and shorter length of hospital stay were observed in the LABF group when compared with the OABF group. All components of the composite event showed the same positive effect in favor of LABF procedure. CONCLUSION: LABF for the treatment of AIOD, Trans-Atlantic Inter-Society Consensus II type D lesions, seems to result in a less composite event when compared with the OABF procedure. To conclude, our results need to be replicated by a randomized clinical trial.