Aria Sana

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.

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.

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.

Waarde van combinatie iFOBT en calprotectine

SamenvattingVraagstelling Er is steeds meer aandacht voor fecesonderzoeken in de eerste lijn. Calprotectine, een eiwit dat bij ontstekingen wordt aangemaakt door neutrofielen en monocyten, lijkt te correleren met de aanwezigheid van een darmontsteking bij inflammatory bowel disease (IBD) zoals de ziekte van Crohn en colitis ulcerosa.1 De immunochemische fecaaloccultbloedtest (iFOBT) wordt gebruikt voor het opsporen van bloed, zoals bij het bevolkingsonderzoek darmkanker. De NHG-Standaarden bevelen beide onderzoeken niet aan.

M1855 Prediction Model for the Diagnosis Chronic Upper Gastrointestinal Ischemia: Diagnostic Value of Symptoms, Radiological Imaging and Gastrointestinal Tonometry

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.