Geoffrey W. Gardiner

High speed, wide velocity dynamic range Doppler optical coherence tomography (Part III): in vivo endoscopic imaging of blood flow in the rat and human gastrointestinal tracts

We previously described a fiber based Doppler optical coherence tomography system [1] capable of imaging embryo cardiac blood flow at 4~16 frames per second with wide velocity dynamic range [2]. Coupling this system to a linear scanning fiber optical catheter design that minimizes friction and vibrations, we report here the initial results of in vivo endoscopic Doppler optical coherence tomography (EDOCT) imaging in normal rat and human esophagus. Microvascular flow in blood vessels less than 100 microm diameter was detected using a combination of color-Doppler and velocity variance imaging modes, during clinical endoscopy using a mobile EDOCT system.

Given capsule endoscopy in celiac disease: evaluation of diagnostic accuracy and interobserver agreement.

BACKGROUND AND AIMS:Capsule endoscopy (CE) has been increasingly used for diagnosing diseases of the small bowel. It is an attractive technique for assessing celiac disease (CD) because it is noninvasive and provides a close and magnified view of the mucosa of the entire small bowel. In this study, we evaluated the accuracy of CE and interobserver agreement in recognizing villous atrophy (VA) using histopathology as the reference. We also explored the extent of small bowel involvement with CD and the relationship between the length of the affected bowel and the clinical presentation.METHODS:Ten CD patients with histologically proven VA and the same number of controls were subjected to CE. Four, blinded to histology findings, investigators (two with and two without prestudy CE experience) were asked to diagnose VA on CE images.RESULTS:Based on assessment of all four investigators, the overall sensitivity, specificity, PPV, and NPV of CE in diagnosing VA were 70%, 100%, 100%, and 77%, respectively. The sensitivity and the specificity of the test was 100% when the reports of experienced capsule endoscopists only were analyzed. The interobserver agreement was perfect (κ= 1.0) between investigators with prestudy CE experience and poor (κ= 0.2) between the investigators who had limited prestudy exposure to CE. Celiac patients with extensive small bowel involvement had typical symptoms of malabsorption (diarrhea, weight loss) as opposed to mild and nonspecific symptoms in patients whose disease was limited to the proximal small bowel. CE was tolerated well by all study participants with 95% reporting absence of any discomfort.CONCLUSIONS:Although based on a small sample size, the study suggests that CE may be useful in assessing patients with CD. Familiarity with CE technology appears to be a critical factor affecting the accuracy of the test. Larger studies are warranted to more precisely define the advantages and limitations of CE in CD.

Endoscopic Doppler optical coherence tomography in the human GI tract: initial experience

BACKGROUND Expanding the current endoscopic optical coherence tomography (OCT) system with Doppler capability may augment this novel high-resolution cross-sectional imaging technique with functional blood flow information. The aim of this feasibility study was to assess the clinical feasibility of an endoscopic Doppler OCT (EDOCT) system in the human GI tract. METHODS During routine endoscopy, 22 patients were imaged by using a prototype EDOCT system, which provided color-Doppler and velocity-variance images of mucosal and submucosal blood flow at one frame per second, simultaneously with high-spatial-resolution (10-25 mum) images of tissue microstructure. The images were acquired from normal GI tract and pathologic tissues. OBSERVATIONS Subsurface microstructure and microcirculation images of normal and pathologic GI tissues, including Barretts esophagus, esophageal varices, portal hypertensive gastropathy, gastric antral vascular ectasia, gastric lymphoma, and duodenal adenocarcinoma, were obtained from 72 individual sites in vivo. Differences in vessel diameter, distribution, density, and blood-flow velocity were observed among the GI tissue pathologies imaged. CONCLUSIONS To our knowledge, this is the first study to demonstrate the feasibility of EDOCT imaging in the human GI tract during routine endoscopy procedures. EDOCT may detect the different microcirculation patterns exhibited by normal and diseased tissues, which may be useful for diagnostic imaging and treatment monitoring.

Nodular regenerative hyperplasia of the liver associated with macroglobulinemia: A clue to the pathogenesis

Nodular regenerative hyperplasia of the liver is an infrequent condition characterized by transformation of the hepatic parenchyma into nodules with only mild fibrosis. Little is known about the etiology except that there is usually an underlying chronic disease, such as Feltys syndrome, which antedates the development of clinical liver disease. It is poorly understood how the associated diseases contribute to the pathogenesis of nodular regenerative hyperplasia. Presented are four cases of nodular regenerative hyperplasia in which macroglobulinemia was also present. This new association suggests to us a hypothesis for the pathogenesis of nodular regenerative hyperplasia. Histologic examination of the livers in these and other cases of nodular regenerative hyperplasia reveals widespread obliteration of the small portal veins. Postmortem angiography of one liver in the present series demonstrated that the nodules were well perfused and that the atrophic areas were poorly perfused with portal blood. This supports the view that atrophy of lobules results from a lack of portal blood supply and that nodules develop from lobules well supplied with portal blood. In each of the clinical conditions associated with nodular regenerative hyperplasia, including macroglobulinemia, inflammatory or thrombotic vascular lesions are found in many organs. Therefore, nodular regenerative hyperplasia may be the hepatic expression of a more widespread vascular disease.

Ramipril-Associated Hepatotoxicity

CONTEXT Angiotensin-converting enzyme inhibitors are prescribed for many cardiovascular and renal diseases. Adverse hepatic events, especially cholestasis, have rarely been reported with captopril, enalapril, lisinopril, and fosinopril. To date, hepatic injury associated with ramipril has not been reported. OBJECTIVE To describe 3 patients who developed hepatitis, with or without jaundice, after receiving ramipril. DESIGN Medical records and liver biopsies of the 3 patients were reviewed. Clinical, laboratory, and histologic findings were compared with findings in other cases of angiotensin-converting enzyme inhibitor-induced liver injury reported in the literature. RESULTS The 3 patients were middle-aged men. In 2 patients, jaundice appeared 4 and 8 weeks after starting ramipril. Bilirubin levels peaked at 15.5 and 5 mg/dL, and alkaline phosphatase values peaked at 957 and 507 U/L. Aminotransferase levels were mildly elevated. Endoscopic retrograde cholangiopancreatography and ultrasonography showed no bile duct obstruction. Liver biopsies from the jaundiced patients were similar, with cholestasis, duct necrosis, and extravasation of bile, ductular proliferation, and portal inflammation. Cholestasis improved in 1 patient 6 weeks after stopping ramipril and was prolonged for 14 months in the other, in whom biliary cirrhosis was present on biopsy. The third patient developed hepatitis without jaundice 3 weeks after starting ramipril; symptoms resolved after stopping the drug. Ramipril-associated liver injury is similar to that seen with other angiotensin-converting enzyme inhibitors, but liver biopsy findings of duct necrosis and extravasation of bile have not been reported previously. CONCLUSION Prolonged cholestatic hepatitis and biliary cirrhosis may result from the use of ramipril. Monitoring of liver enzymes is advisable for patients starting on ramipril.

Does whipworm increase the pathogenicity of Campylobacter jejuni? A clinical correlate of an experimental observation

Campylobacter jejuni is a leading cause of acute diarrhea worldwide, usually mild and self-limiting. No adequate hypothesis has yet been formulated to explain why in an otherwise healthy host this infection is occasionally severe. In a pig model, C jejuni has been shown to be pathogenic only in the presence of swine whipworm. A human case of life-threatening C jejuni colitis leading to toxic megacolon and acute renal failure, associated with concomitant whipworm (Trichuris suis) ova in the feces, is reported. The potential of T suis to potentiate C jejuni in humans deserves further study.

Kayexalate (sodium polystyrene sulphonate) in sorbitol associated with intestinal necrosis in uremic patients

BACKGROUND Kayexalate (sodium polystyrene sulphonate) in sorbitol is commonly used to treat hyperkalemia in patients with renal insufficiency. Isolated case reports and one recent large series have documented intestinal necrosis following administration of kayexalate in sorbitol. METHODS Two patients with luminal kayexalate crystals associated with intestinal pathology were first identified in the pathology department, and clinicopathological correlation was carried out. RESULTS Both patients were seriously ill, had prior cardiac surgery and were in renal failure (uremic). Examination of autopsy and colonic resection showed luminal kayexalate crystals associated with underlying mucosal necrosis, submucosal edema and transmural inflammation. CONCLUSION Although occurring in complex clinical settings, the pathological findings provide additional evidence that kayexalate in sorbitol may be associated with intestinal necrosis and inflammation in uremic patients and that this may be a clinically and pathologically under-recognized iatrogenic bowel injury.

Omega-3-enriched lipid emulsion for liver salvage in parenteral nutrition-induced cholestasis in the adult patient.

The intrahepatic cholestasis attributed to parenteral nutrition (PN) in the adult patient is relatively rare and usually occurs in patients receiving long-term PN. This article reports the first case of an adult patient with cholestatic PN-associated liver disease without sepsis who received almost all her nutrition requirements through PN. Administration of an ω-3-enriched lipid emulsion added to the PN regimen reversed cholestasis and demonstrated histologic improvement on serial liver biopsy. The patient had failed to respond to other modalities of treatment for this condition and was deeply jaundiced. Liver biochemistry profiles returned to baseline, and follow-up liver biopsy showed that cholestasis had resolved and that the only residual changes were mild portal inflammation with no histochemical or ultrastructural progression. The PN regimen for the patient was restored to provide total estimated energy requirements and remains the principle source of the patients nutrition to date.

NSAID injury to the small intestine

AbstractPurpose: To identify the clinical and radiologic findings in patients with diaphragm-like strictures in the small bowel. Patients and methods: We reviewed the histories, radiologic findings, and pathologic findings in two men and two women, all in their sixties, with a history of long-term nonsteroidal antiinflammatory drug (NSAID) or aspirin (ASA) usage and one or more radiologically demonstrated diaphragm-like strictures in the small bowel. Results: Two patients had long histories of NSAID usage, and two of ASA usage. One NSAID user had a long segment of jejunal involvement, and the other three had short segments of duodenal involvement. The ASA users presented with symptoms of esophageal disease, the small bowel lesions were unexpected, and ASA usage was not initially elicited. In one NSAID user and one ASA user, broader strictures with humps rather than diaphragms were also seen producing a lifesaver-like or bagel-like configuration. Conclusions: Multiple diaphragm-like strictures can occur in NSAID injury and are pathognomonic except in the rare patient with ulcerative enteritis complicating celiac disease. Single or few diaphragm-like strictures can occur in NSAID injury and peptic ulceration. ASA should be considered an NSAID with regard to small-bowel toxicity. A careful medication history is required when an unexplained small bowel abnormality is seen radiologically, and a dedicated small bowel examination is required when NSAID injury is suspected.

Gastric calcifying fibrous tumour

Intramucosal gastric tumours are most commonly found to be gastrointestinal stromal tumours or leiomyomas (smooth muscle tumours); however, a variety of other uncommon mesenchymal tumours can occur in the stomach wall. A rare benign calcifying fibrous tumour is reported and the endoscopic appearance, ultrasound findings and morphology are documented. A review of the literature found only two similar cases.