Désirée van Noord

Endoscopic visible light spectroscopy: a new, minimally invasive technique to diagnose chronic GI ischemia

BACKGROUND The diagnosis of chronic GI ischemia (CGI) remains a clinical challenge. Currently, there is no single simple test with high sensitivity available. Visible light spectroscopy (VLS) is a new technique that noninvasively measures mucosal oxygen saturation during endoscopy. OBJECTIVE To determine the diagnostic accuracy of VLS for the detection of ischemia in a large cohort of patients. DESIGN Prospective study, with adherence to the Standards for Reporting of Diagnostic Accuracy. SETTING Tertiary referral center. PATIENTS Consecutive patients referred for evaluation of possible CGI. INTERVENTIONS Patients underwent VLS along with the standard workup consisting of evaluation of symptoms, GI tonometry, and abdominal CT or magnetic resonance angiography. MAIN OUTCOME MEASUREMENTS VLS measurements and the diagnosis of CGI as established with the standard workup. RESULTS In 16 months, 121 patients were included: 80 in a training data set and 41 patients in a validation data set. CGI was diagnosed in 89 patients (74%). VLS cutoff values were determined based on the diagnosis of CGI and applied in the validation data set, and the results were compared with the criterion standard, resulting in a sensitivity and specificity of VLS of 90% and 60%, respectively. Repeated VLS measurements showed improvement in 80% of CGI patients after successful treatment. LIMITATIONS Single-center study; only 43% of patients had repeated VLS measurements after treatment. CONCLUSIONS VLS during upper endoscopy is a promising easy-to-perform and minimally invasive technique to detect mucosal hypoxemia in patients clinically suspected of having CGI, showing excellent correlation with the established ischemia workup.

Single vessel abdominal arterial disease

The long-standing discussion concerning the mere existence of single vessel abdominal artery disease can be closed: chronic gastrointestinal ischaemia (CGI) due to single vessel abdominal artery stenosis exists, can be treated successfully and in a safe manner. The most common causes of single vessel CGI are the coeliac artery compression syndrome (CACS) in younger patients, and atherosclerotic disease in elderly patients. The clinical symptoms of single vessel CGI patients are postprandial and exercise-related pain, weight loss, and an abdominal bruit. The current diagnostic approach in patients suspected of single vessel CGI is gastrointestinal tonometry combined with radiological visualisation of the abdominal arteries to define possible arterial stenosis. Especially in single vessel abdominal artery stenosis, gastrointestinal tonometry plays a pivotal role in establishing the diagnosis CGI. First-choice treatment of single vessel CGI remains surgical revascularisation, especially in CACS. In elderly or selected patients endovascular stent placement therapy is an acceptable option.

Serum Markers and Intestinal Mucosal Injury in Chronic Gastrointestinal Ischemia

BackgroundDiagnosing chronic gastrointestinal ischemia (CGI) is a challenging problem in clinical practice. Serum markers for CGI would be of great diagnostic value as a non-invasive test method.AimsThis study investigated serum markers in patients with well-defined ischemia. Furthermore, intestinal mucosal injury was also evaluated in CGI patients.MethodsConsecutive patients suspected of CGI were prospectively enrolled and underwent a diagnostic work-up consisting of gastrointestinal tonometry and either CT or MR angiography. Blood samples for analysis of intestinal fatty acid-binding protein (I-FABP), D-dimer, lactate dehydrogenase (LDH), leucocyte counts, C-reactive protein (CRP), and L-lactate were drawn before and after a standard meal. Intestinal mucosal injury was assessed with glutamine, citrulline and arginine in blood samples and compared to a sugar absorption test (SAT). Test reproducibility was validated in healthy subjects.ResultsForty patients and nine healthy subjects were included. Ischemia was diagnosed in 32 patients (80%). I-FABP, leucocyte counts, LDH, CRP, glutamine, citrulline, arginine and SAT levels did not differ between patients with and without ischemia. L-lactate concentration showed a significant elevation in ischemia patients as compared to non-ischemia patients. In ischemia patients, D-dimer levels showed a significant elevation postprandially as compared to D-dimer levels at baseline. However, these ischemia patients did not show intestinal mucosal injury.ConclusionsI-FABP, leucocyte counts, LDH and CRP levels are not clinically useful for the diagnosis of CGI. However, postprandial rises in L-lactate and D-dimer serum levels can serve as non-invasive indicators of CGI.

Radiological Imaging and Gastrointestinal Tonometry Add Value in Diagnosis of Chronic Gastrointestinal Ischemia

BACKGROUND & AIMS The diagnosis of chronic gastrointestinal ischemia (CGI) remains a clinical challenge. We aimed to assess the diagnostic value of clinical features, visualization of the gastrointestinal arteries, and evaluation of mucosal perfusion in patients clinically suspected of CGI. METHODS A total of 186 patients referred for suspicion of CGI were prospectively included and followed up. All patients had an extensive diagnostic work-up, including visualization of the gastrointestinal arteries with computed tomography, magnetic resonance, or conventional angiography, and mucosal perfusion with tonometry. The reference standard for CGI was persistent clinical response after adequate therapy. The diagnostic value of individual and combined tests was assessed with multivariable logistic regression analysis. RESULTS A total of 116 (62%) patients were diagnosed with CGI. In a multivariable model solely based on clinical features, the strongest predictors for CGI were the presence of postprandial pain, weight loss per month in kilograms, concomitant cardiovascular disease, and presence of an abdominal bruit. However, this model showed limited discriminative ability for the presence or absence of CGI (c-statistic, 0.62). Adding radiologic imaging to the prediction model improved the discriminative ability substantially (c-statistic, 0.81). Adding tonometry to the prediction model further improved the discriminative ability of the model (c-statistic, 0.90). The combination of clinical features and tonometry with a c-statistic of 0.88 approximated the discriminative ability of the latter model. CONCLUSIONS Clinical features alone have a limited value to assess CGI correctly. Visualization of the gastrointestinal arteries and evaluation of mucosal perfusion substantially improve the diagnosis of CGI. The strongest diagnostic contribution comes from mucosal perfusion assessment.

Use of visible light spectroscopy to diagnose chronic gastrointestinal ischemia and predict response to treatment

BACKGROUND & AIMS Chronic gastrointestinal ischemia (CGI) is more common than previously thought. Visible light spectroscopy (VLS) allows for noninvasive measurements of mucosal capillary hemoglobin oxygen saturation during endoscopy. We evaluated the response of patients with occlusive CGI to treatment after evaluation by radiologic imaging of the vasculature and VLS. We also identified factors associated with response to treatment in these patients. METHODS In a prospective study, we collected data from 212 patients referred for evaluation of suspected CGI from November 2008 through January 2011. Patients underwent an extensive evaluation that included visualization of gastrointestinal arteries and assessments of mucosal perfusion by means of VLS. Treatment response was evaluated in patients with occlusive CGI. Factors associated with response to therapy were assessed by using multivariate logistic regression analysis. RESULTS Occlusive CGI was diagnosed in 107 patients (50%); 96 were offered treatment (90%). After median follow-up period of 13 months, data on treatment response were available from 89 patients (93%); 62 patients had a sustained response (70%). Weight loss before treatment (odds ratio [OR], 1.93), presence of an abdominal bruit (OR, 2.36), and corpus mucosal saturation level <56% (OR, 4.84) were the strongest predictors of a positive response to treatment. CONCLUSIONS Treatment of CGI, diagnosed by a multimodal approach, provides a substantial long-term rate of response (70% in 13 months). Weight loss, abdominal bruit, and low corpus mucosal saturation identify patients most likely to respond to treatment. Multiple techniques should therefore be used to assess patients with CGI, including VLS measurements, to detect mucosal hypoxia.

Histological changes in patients with chronic upper gastrointestinal ischaemia

van Noord D, Biermann K, Moons L M G, Pattynama P M T, Verhagen H J M, Kuipers E J & Mensink P B F
(2010) Histopathology57, 615–621
Histological changes in patients with chronic upper gastrointestinal ischaemia

Combining radiological imaging and gastrointestinal tonometry: a minimal invasive and useful approach for the workup of chronic gastrointestinal ischemia.

Background The established approach for patients suspected of chronic gastrointestinal ischemia (CGI) includes assessment of medical history, vascular imaging, such as by digital subtraction angiography, and, more recently, computed tomography angiography (CTA) or magnetic resonance angiography. Mucosal perfusion assessment techniques have recently been shown to be of additional diagnostic value, including visible light spectroscopy and gastric exercise tonometry. Gastric exercise tonometry, however, is cumbersome and impossible to perform in a considerable proportion of patients. An alternative approach is provided by 24 h gastrointestinal tonometry (TM). We challenged the use of TM in combination with CTA as an alternative approach to evaluate patients suspected of CGI. Methods Patients referred for suspected CGI were prospectively evaluated using CTA and TM, and discussed in a multidisciplinary team, where a consensus diagnosis was made. CGI patients were offered therapy. Persistent symptom relief after adequate therapy during follow-up was used as the ‘gold standard’ and was defined as a definitive diagnosis of CGI. Results In 31 months, 186 patients were included (men 69, mean age 63 years). A consensus diagnosis of CGI was made in 128 (69%) patients: 94 with occlusive and 34 with nonocclusive CGI. After a median follow-up of 21 months after a therapeutical intervention, 91% of the CGI patients were free from symptoms. Conclusion In patients clinically suspected of CGI, the combination of CTA and TM provides a minimally invasive, reliable diagnostic approach, which seems to be very useful in clinical practice and to have an outcome similar to the established diagnostic workup.

Functional testing in the diagnosis of chronic mesenteric ischemia

Chronic mesenteric ischemia (CMI) results from insufficient oxygen delivery or utilization to meet metabolic demand. Two main mechanisms may lead to mesenteric ischemia: occlusion in the arteries or veins of the gastrointestinal tract, or reduced blood flow from shock states or increased intra-abdominal pressure, so-called non-occlusive mesenteric ischemia. Severe stenoses in the three main mesenteric vessels as demonstrated with CT-angiography or MR-angiography are sufficient to proof mesenteric ischemia, for example in patients who present with weight loss, postprandial pain and diarrhea. Still in many clinical situations mesenteric ischemia is only one of many possible explanations. Especially in patients with a single vessel stenosis in the celiac artery or superior mesenteric artery with postprandial pain, mesenteric ischemia remains a diagnosis of probability or assumption without functional proof of actual ischemia. This review is aimed to provide an overview of all past, present and future ways to functionally proof CMI.

GI ischemia in patients with portal vein thrombosis: A prospective cohort study

BACKGROUND AND AIMS GI ischemia is a concerning adverse event of portal vein thrombosis (PVT). Minimally invasive techniques, such as visible light spectroscopy (VLS), have greatly improved the ability to diagnose GI ischemia. The aim of this study was to assess the clinical presentation and characteristics of GI ischemia in patients with PVT. METHODS Patients with noncirrhotic, nonmalignant PVT were included in this prospective cohort study. Clinical symptoms of GI ischemia were assessed by a structured questionnaire, VLS, and radiologic evaluation of the mesenteric vasculature. VLS measurements were compared with those in patients with cirrhosis and with a reference population. RESULTS We included 15 patients with chronic PVT and 1 patient with acute PVT (median age 46.1 years [interquartile range [IQR], 30.9-53.7]; 44% male). Decreased mucosal oxygenation in at least 1 location of the GI tract was found in 12 patients (75%). Compared with the reference population (median 60.0 [IQR, 56.2-61.7]), VLS measurements were mostly decreased in the descending duodenum in patients with PVT (median 55.5 [IQR, 52.3-58.8]; P = .02) and patients with cirrhosis (median 52.0 [IQR, 46.5-54.0], P = .003). Symptoms typical for GI ischemia, such as postprandial pain and exercise-induced pain, were reported in 10 patients (63%) with PVT. In patients with extension of thrombosis into the superior mesenteric vein and splenic vein and/or presence of hypercoagulability, decreased VLS measurements were observed compared with historical control subjects. CONCLUSIONS In patients with chronic PVT, GI ischemia is frequent. VLS enables objective and quantitative determination of GI mucosal ischemia. Onset of abdominal symptoms such as postprandial pain should prompt the physician to re-evaluate extent, cause, and treatment of PVT.

M1859 Serum Markers and Intestinal Mucosal Injury in Chronic Upper Gastrointestinal Ischemia

HS + Day 5 FFP and HS + LR (n = 4-7 per group). Rats were hemorrhaged by removing 2 ml of blood/100 g of body weight. One hour later, the rats were resuscitated with either Day 0 FFP, Day 5 FFP (1x volume of shed blood) or LR (3x volume of shed blood). Mean arterial pressure (MAP) was continuously recorded for 6 h after resuscitation. All 3 treatment groups (HS + Day 0 FFP, HS + Day 5 FFP and HS + LR) significantly restored HS-induced decreased in blood pressure with no significant differences among the 3 treatment groups. Jejunum tissue samples were collected 6 h after resuscitation and fixed in formalin for sectioning. Chiu scores were performed to evaluate the overall injury to the gut tissues (05, 0 being normal, 5 being the worst). Our data showed that Chiu score was significantly higher in HS alone group than Sham group (3.00 ± 0.57 vs 0.13 ± 0.13, p<0.01). Resuscitation with Day 0 FFP resulted in a lower Chiu score (1.00 ± 0.11) compared to HS alone group and LR resuscitated group (1.75 ± 0.25) and was significantly better than Day 5 FFP group (2.58 ± 0.20). Apoptosis was examined in gut vascular cells using a VasoTACS in situ apoptosis detection kit. Apoptosis was significantly reduced in HS + Day 0 FFP group compared to HS alone, HS + Day 5 FFP and HS + LR. From these results, we conclude that resuscitation with FFP protects the gut from HS-induced injury. Furthermore, standard FFP storage may attenuate FFPs beneficial effects in the gut.