In vivo 1 H MRS of human gallbladder bile in understanding the pathophysiology of primary sclerosing cholangitis (PSC): Immune-mediated disease versus bile acid-induced injury

Primary sclerosing cholangitis (PSC) has been considered to be either an "autoimmune disease" or a "bile acid-induced injury." In vitro MRS studies on PSC patients have limitations due to the contamination of bile with contrast agent (commonly administered during endoscopic retrograde cholangiopancreatography) and/or the use of patient cohorts with other diseases as controls. The objective of this study was to quantify biliary metabolites using in vivo ¹ H MRS and gain insight into the pathogenesis of PSC. Biliary metabolites in 10 PSC patients and 14 healthy controls were quantified in vivo using ¹ H MRS on a 3 T MR scanner. The concentrations of total bile acids plus cholesterol, glycine-conjugated bile acids, taurine-conjugated bile acids, and choline-containing phospholipids (chol-PLs) were compared between the two groups. There were statistically significant decreases in the levels of the above mentioned biliary metabolites in the PSC patients compared with controls. The reduction in bile acid secretion in bile of PSC patients indicates accumulation of bile acids in hepatocytes. Moreover, reduction in the levels of chol-PLs in bile may increase the toxic effects of bile acids. Our findings suggest that the bile duct injury in PSC patients is most likely due to "bile acid-induced injury."

Effect of severe gastroesophageal reflux on sleep stage in patients with aperistaltic esophagus

Polysomnography and esophageal pH studies were conducted in 13 patients with an aperistaltic esophagus; seven of these had scleroderma and six were patients treated for achalasia. The percentage total time of pH<4.0 when recumbent exceeded 30% for both groups. There was a total of 51 reflux events for both groups. There were 22 reflux events recorded for both groups that were less than 5 min in length and 29 events greater than 5 min. In 26 of 32 (81%) instances, patients either began awake and went to sleep during a reflux event or did not awake during a reflux event. Only six of 32 (19%) reflux events caused sleep disruption. We conclude that even the severe reflux demonstrated in this subset of patients does not always disrupt sleep. Patients may have severe prolonged reflux and not arouse.

Reflux in untreated achalasia patients

We made a prospective assessment of acid exposure in the distal esophagus in 48 consecutive untreated patients with achalasia using 24-h ambulatory esophageal pH studies. The majority of patients (38/48) experienced reflux that was within reported values for normal controls (total time pH < 4.0, 1.8 +/- 1.9%). Approximately 20% (10/48), however, demonstrated abnormal acid exposure (total time pH < 4.0, 18.8 +/- 14.8%). The difference in reflux expressed by these two groups was not due to a significant difference in lower esophageal sphincter pressure (p > 0.05) or retained food. An in vitro model of lactobacillus fermentation supported the contention that true acid reflux accounted for changes in esophageal pH. Repeat pH studies were obtained in 23 patients following treatment: 15 underwent pneumatic dilatation and 8 underwent limited myotomy. Although no significant differences were found between pre- and posttreatment reflux, some patients undergoing either treatment were found to demonstrate increased acid exposure. In conclusion, we believe that patients with achalasia should be tested by pH study both before and after treatment. Most of the patients who demonstrated significant pretreatment reflux were asymptomatic, and both methods that were used to decrease resting sphincter pressure were shown to be able to increase distal acid exposure.

The effect of nasal CPAP on nocturnal reflux in patients with aperistaltic esophagus

It has been shown that nasal continuous positive airway pressure (nasal CPAP) significantly reduces nocturnal reflux both in patients with sleep apnea and in patients without sleep apnea but consistent abnormal nocturnal reflux. The mechanism by which CPAP is thought to reduce reflux includes the elevation of the resting lower esophageal sphincter (LES) pressure. In this study, we tested the effect of nasal CPAP in two groups of patients with aperistaltic esophagus but with different resting LES pressure. Seven patients with scleroderma esophagus and six patients treated for achalasia were tested over a 48-h period. On the first night, the patients were untreated; on the second night, both groups received applied nasal CPAP at 8 cm H2O pressure. The percentage of time the pH < 4.0, the number of reflux events > 5 min, and the length of the longest reflux event were all significantly reduced in the patients with achalasia (p < 0.03), but not in the scleroderma group (p > 0.20). These results suggest that a residual resting LES pressure greater than that demonstrated by patients with scleroderma (> 10 mm Hg) may be necessary for nasal CPAP to affect nocturnal reflux.

Reflux after esophagectomy and interposition of right colon

OBJECTIVE

To determine the nature of reflux after esophagectomy and interposition of right colon.

DESIGN

A case series.

SETTING

A university hospital.

PATIENTS

Five patients (mean age 43 years) in whom right colon had been interposed after total esophagectomy.

INTERVENTIONS

Endoscopy and biopsy, manometry, 24-hour ambulatory pH testing.

MAIN OUTCOME MEASURES

Endoscopic and histologic appearances of the colon, type of motor activity in the grafted colon and the type of reflux.

RESULTS

In all patients the grafted colon was macroscopically and microscopically normal. There was nonperistaltic motor activity in the interposed colon in two patients. All patients had an abnormal pattern of alkaline reflux, and one patient had abnormal acid reflux.

CONCLUSIONS

The clinical effect of alkaline reflux in patients with colonic interposition after total esophagectomy may be slight. Histologic and gross changes are likely to be minimal.

Comparison of magnetic resonance imaging and endoscopy in distinguishing the type and severity of inflammatory bowel disease

Twenty consecutive patients with first-time presentation of suspected inflammatory bowel disease underwent both endoscopy with biopsy and magnetic resonance imaging (MRI) within a 3-day period; the relative abilities of endoscopy and MRI to distinguish ulcerative colitis (UC) from Crohn's disease (CD) and to determine the severity of the disease process were compared. In 18 of 20 patients, a diagnosis of UC or CD could be made on histological specimens. MRI correctly diagnosed 17 of these 18 patients using T1-weighted fat-suppressed spin echo and gadolinium enhancement. Endoscopy correctly diagnosed 15 patients. Overall, MRI was not significantly better (p > 0.05) than endoscopy in distinguishing UC from CD. MRI correctly graded the severity of inflammatory changes in 13 of 20 patients, and endoscopy did so in 11 of 20. MRI and endoscopy findings were within one grade of histology findings in seven patients each. No significant difference (p > 0.05) was found between MRI and endoscopy in the ability to estimate the severity of the disease (as determined from biopsies). Bowel wall thickness measured on MR images demonstrated good correlation with percentage of contrast enhancement: r = 0.61; p = 0.003. In sum, magnetic resonance imaging was shown to be comparable with endoscopy in differentiating UC from CD and in gauging the severity of disease. Transmural assessment, sagittal imaging, and the lack of invasiveness were attractive features of MRI.

Solitary hepatic metastasis: comparison of dynamic contrast-enhanced CT and MR imaging with fat-suppressed T2-weighted, breath-hold T1-weighted FLASH, and dynamic gadolinium-enhanced FLASH sequences

Twenty consecutive cancer patients with a solitary hepatic metastasis detected with dynamic contrast-material-enhanced computed tomography (CT) who were considered for hepatic resection underwent magnetic resonance (MR) imaging within 18 days after CT. Histologic confirmation was obtained in all lesions. CT depicted 20 solitary lesions. MR imaging showed a solitary lesion in 14 patients, two lesions in three patients, and more than two lesions in three patients, for a total of 37 lesions. Twenty-three lesions less than 2 cm in diameter were missed with CT, and six lesions less than 1.3 cm in diameter were missed with MR imaging. MR imaging was superior to CT in the detection of hepatic metastases on a patient-by-patient basis (P < .01). The results suggest that MR imaging is superior to dynamic contrast-enhanced CT for the detection of hepatic metastases.

Nasal continuous positive airway pressure. A new treatment for nocturnal gastroesophageal reflux?

Nasal continuous positive airway pressure (CPAP) reduces nocturnal gastroesophageal reflux (GER) in obstructive sleep apnea syndrome (OSAS) patients. The primary objectives of our investigation were to determine if CPAP could reduce reflux in non-OSAS patients and, if so, by what mechanism. Esophageal pH was monitored for 48 h in six nocturnal reflux patients. During the first 24 h, basal reflux data were collected; the second night, nasal CPAP was administered (pressure = 8 cm H2O). Esophageal manometry was obtained in six healthy adult volunteers both on and off nasal CPAP (pressure = 8 cm H2O) to ascertain CPAP's effects on esophageal pressure and peristalsis. The six reflux patients experienced less nocturnal GER while on CPAP. The mean percent time esophageal pH < 4 was reduced from 27.7 +/- 10.0 to 5.8 +/- 2.6 (p < 0.004); the mean reflux duration dropped from 2.1 +/- 0.6 to 0.9 +/- 0.5 min (p < 0.03); and the mean duration of longest reflux improved from 84.3 +/- 32.6 to 13.8 +/- 6.9 min (p < 0.01). The CPAP raised the mean resting midesophageal pressure by 4.4 cm H2O (p < 0.01) and the mean resting lower esophageal pressure (LES) by 13.2 cm H2O (p < 0.02) in the healthy volunteers. Nasal CPAP effectively reduced nocturnal GER in six patients with nocturnal reflux. The antireflux activity of CPAP is likely due to passive elevation of intraesophageal pressure and possibly to reflex LES constriction.

Magnetic resonance imaging evaluation of the local extent of colorectal mass lesions

Magnetic resonance imaging (MRI) was conducted in 21 patients with known or suspected colorectal mass lesions. Imaging was carried out at 1.5 T using Fast Low Angle Shot (FLASH) and fat-suppressed (T1FS) gadolinium enhanced sequences. The lesions studied included adenocarcinoma (n = 16), lipoma (n = 2), villous adenoma with foci of adenocarcinoma (n = 1), malignant melanoma (n = 1), and rectal lymphoma (n = 1). Correlation was made with surgical findings in 14 patients, 10 of whom had tumors resected. Bowel wall involvement, tumor size, and extension demonstrated on MR images was correlated with histopathology findings. No significant differences were found (p > 0.05) among those parameters when compared to MR information from T1FS images. Lymph nodes were demonstrated on MR images but distinction between benign and malignant nodes could not be made.

The extent and pattern of gastro-oesophageal reflux in patients with scleroderma oesophagus: the effect of low-dose omeprazole

Ambulatory 24-hour oesophageal pH studies were obtained from 11 patients with scleroderma who expressed either dysphagia (n = 6) or heartburn (n = 5) as their predominant oesophageal symptom. No significant differences were found in the extent of pattern of reflux between these two groups. The pH data of both scleroderma groups were combined and compared to an age- and sex-matched group of control subjects (n = 11). The reflux demonstrated by scleroderma patients was significantly greater than the control group in every category (P < 0.01). The percentage of time the pH was < 4.0 was not significantly different (P > 0.05) upright (29.9 +/- 19.8%) vs. supine (44.2 +/- 28.5%) in patients with scleroderma. Eight scleroderma patients underwent repeat pH studies while taking low-dose omeprazole (20 mg daily) and reflux was reduced significantly (P < 0.01) in all patients. The authors believe that 24-hour ambulatory oesophageal pH-monitoring should be routinely conducted in scleroderma patients to provide quantitative reflux data, even when heartburn is not expressed as a symptom. Omeprazole, 20 mg daily, provides adequate protection from the H+ component of the refluxate.

MRI in the diagnosis of Crohn's disease in two pregnant women

Two pregnant women considered symptomatic for inflammatory bowel disease were referred for magnetic resonance imaging (MRI) for assistance in establishing a diagnosis. Breath-hold gradient echo and contrast-enhanced T1-weighted fat-suppressed spin echo sequences were used. The MR appearance of the terminal ileum was consistent with Crohn's disease in both patients. The diagnosis of Crohn's disease was subsequently confirmed histologically. MRI is a safe, noninvasive modality that may be useful in confirming a suspected diagnosis of inflammatory bowel disease, especially in patients who cannot be evaluated with standard techniques.

Magnetic resonance imaging in inflammatory bowel disease

Magnetic resonance (MR) images were acquired in 28 consecutive inflammatory bowel disease (IBD) patients undergoing medical treatment. The protocol employed included i.v. gadopentatate dimeglumine, pre- and post-contrast breath-hold Fast Low Angle Shot (FLASH), and fat-suppressed spin echo imaging. The percent contrast enhancement (% CE) of the fat-suppressed images was compared with severity of inflammation based on endoscopic and/or surgical findings. The %CE of the contrast-enhanced images was 169% +/- 63 in cases of severe inflammation (n = 16), 97% +/- 38 in moderate inflammation (n = 8), and 49% +/- 26 in mild inflammation (n = 4). Significant correlations were found between the clinicopathologic findings and (a) % CE, r = 0.74 (p = 0.0001); (b) length of affected bowel segment, r = 0.49 (p = 0.007); and (c) bowel wall thickness, r = 0.42 (p = 0.02). In a subsequent comparison, %CE was correlated with length of affected bowel and bowel wall thickness. The best correlation was bowel wall thickness, r = 0.53 (p < 0.004). Good correlation was found between MR findings and pathology/histology findings in the determination of bowel wall thickness, length of diseased bowel, and severity of inflammation in 10 patients who underwent bowel resection. The results of this study show that MR images demonstrate the extent and severity of inflammatory changes in the GI tract, which correlate with endoscopic and histological findings.

Chronic pancreatitis: MR imaging features before and after administration of gadopentetate dimeglumine

Magnetic resonance (MR) imaging was performed in patients with a history (> 1 year) of inflammatory pancreatic disease. Calcification was seen at recent computed tomographic examinations in 13 patients and was not seen in nine patients. On fat-suppressed spin-echo images, the signal-to-noise ratio of the pancreas was significantly lower (P < .001) in patients with pancreatic calcification (18.2 +/- 2.5 vs 38.1 +/- 6.1). On fast low-angle shot images, the percentage of contrast enhancement was also significantly lower (P < .001) in patients with calcification (26.1% +/- 5.8 vs 78.7% +/- 15.9). The results suggest that MR imaging may be useful in evaluating patients with a long history of pancreatic disease for the presence of irreversible disease.

Bile duct disease: prospective comparison of ERCP, CT, and fat suppression MRI

The authors compared computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP), techniques commonly used to study the biliary tree, with pre- and post-Gd-DTPA breath-hold fast low angle shot (FLASH) and fat suppressed spin-echo in 28 consecutive patients with bile duct abnormalities detected on ERCP, including 11 patients with malignant disease and 17 patients with benign disease. ERCP, CT, and magnetic resonance (MR) images were prospectively interpreted in a blinded fashion and reviewed by consensus. ERCP characterized all cases of malignant disease by the presence of a narrowed bile duct lumen with irregular margins. CT and MRI detected all cases of malignant disease and characterized nine of 11 as malignant. In seven of these cases, CT and MRI showed thickening of extrahepatic bile duct walls greater than 5 mm. MRI images showed intrahepatic-enhancing periportal tissue in four cases, which was not seen on CT images, and which was biopsy-proven tumor extension. Benign disease was characterized on ERCP images by the demonstration of smooth tapered narrowings in 16 cases, whereas on CT and MR images it was characterized by mild to moderate dilatation of the intrahepatic bile ducts and wall thickness less than 5 mm in 13 cases. Overall ERCP correctly characterized 27 cases as benign or malignant and CT and MRI both characterized 25. The results of this study show a trend that ERCP is superior to CT and MRI for characterizing bile duct disease.

Focal liver disease: comparison of dynamic contrast-enhanced CT and T2-weighted fat-suppressed, FLASH, and dynamic gadolinium-enhanced MR imaging at 1.5 T

Dynamic contrast medium-enhanced computed tomography (CT), T2-weighted fat-suppressed spin-echo (T2FS) magnetic resonance (MR) imaging, and breath-hold T1-weighted fast low-angle shot (FLASH) MR imaging before and after dynamic gadopentetate dimeglumine injection were compared in 73 patients with clinically suspected liver disease. Observer confidence for presence of focal lesions was determined by using receiver operating characteristic analysis. For all MR images, hepatic lesion-liver signal-to-noise ratios were evaluated qualitatively. and resolution and presence of artifacts were evaluated qualitatively. Lesion detection was greatest with T2FS (n = 272) and enhanced FLASH (n = 244) and was statistically greater with both of these than with CT (n = 220) and FLASH (n = 219) (P less than .03). Correct lesion characterization was greatest with enhanced FLASH (n = 236) (P less than .01), followed by CT (n = 199), FLASH (n = 164), and T2FS (n = 144). Enhanced FLASH was particularly successful in characterization of 5-mm- to 1.5-cm-diameter lesions as cystic or solid.

Pancreatic disease: prospective comparison of CT, ERCP, and 1.5-T MR imaging with dynamic gadolinium enhancement and fat suppression

New magnetic resonance (MR) imaging techniques possess features desirable for imaging the pancreas. Computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) were prospectively compared with breath-hold fast low-angle shot (FLASH) and fat-suppressed spin-echo techniques before and after enhancement with gadopentetate dimeglumine. Thirty-five patients underwent ERCP, CT, and/or MR imaging studies within a 1-month period. Correlation with surgical findings, histologic findings, or clinical and/or imaging follow-up was obtained in all cases. Quantitative measurements of pancreas, pancreas minus pancreatic lesion, and pancreas minus fat signal-to-noise ratios (SNRs) were performed on MR images. The highest measurements of pancreas minus pancreatic tumor SNR were on gadolinium-enhanced, fat-suppressed images (8.9 +/- 3.4). The 1-second postcontrast FLASH images most reliably showed enhancement of normal pancreatic tissue. Nonenhanced FLASH images depicted peripancreatic fluid and inflammatory changes most successfully. The findings from this study suggest MR imaging is effective for imaging inflammatory and neoplastic pancreatic disease and may be superior to CT.

Bowel disease: prospective comparison of CT and 1.5-T pre- and postcontrast MR imaging with T1-weighted fat-suppressed and breath-hold FLASH sequences

The potential of new high-field-strength magnetic resonance (MR) imaging sequences to evaluate bowel disease was investigated and compared with computed tomographic (CT) studies. Thirty-two patients were studied, 14 with known or suspected gastrointestinal tumors and 18 with known or suspected bowel inflammatory conditions. T1-weighted fat-suppressed spin-echo and breath-hold FLASH (fast low-angle shot) images were obtained before and after intravenous injection of 0.1 mmol/kg gadopentetate dimeglumine. Pathologic confirmation was obtained by biopsy (n = 18), surgical excision (n = 8), or endoscopy (n = 6). CT and MR images were analyzed separately in a prospective fashion and reviewed by consensus. Information from CT and MR images was comparable in cases of confirmed bowel neoplasia. CT scans had better spatial resolution, while fat-suppressed gadolinium-enhanced MR images had better contrast resolution. In the 18 cases of bowel inflammation, CT scans showed concentric wall thickening in 16, while MR images showed concentric wall thickening in 14 and increased contrast enhancement in 17. Contrast enhancement was better appreciated on fat-suppressed images than on FLASH images. The results suggest that MR imaging may play a role in the evaluation of bowel disease.

Esophageal reflux before and after isolated myotomy for achalasia

Four patients with achalasia underwent 24-hour esophageal pH measurements as ambulatory patients before and after limited myotomy without fundoplication. Resting lower esophageal sphincter pressure was reduced from 24.3 +/- 1.3 mm Hg to 7.5 +/- 4.3 mm Hg. No significant differences (p greater than 0.05) were found before and after operation in the total 24-hour pH data distribution (pH 6.24 +/- 0.84 vs 5.75 +/- 1.03), the fraction of time below pH 4.0 (4.8% +/- 5.3% vs 8.0% +/- 6.9%), or the mean duration of reflux episodes greater than 5 minutes (22.8 +/- 18.8 minutes vs 23.0 +/- 10 minutes), all +/- SD. Effective relief of esophageal obstruction in achalasia is feasible by isolated limited myotomy without producing gastroesophageal reflux.

A new direct portosystemic collateral in canine portal hypertension

Two different models of extrahepatic portal obstruction were prepared in dogs to examine the development of portosystemic collateral pathways. The collateral pathways that developed were of two main types, portosplenic communications with the azygos system and a direct communication between the portal vein complex and the intrathoracic part of the inferior vena cava (IVC). This direct communication between the portal venous system and the IVC was unknown to us prior to these studies. The channel we describe has a potential for directly inducing pulmonary embolism, a possibility not seriously considered so far.

Reflux patterns in patients with achalasia without operation

Five patients with achalasia who had not had an operation underwent esophageal manometry and 24-hour, ambulatory pH monitoring to determine the pattern and extent of esophageal reflux. One patient had reflux within normal limits. In 2 patients, reflux occurred 0.5% of the total time and no episodes of supine reflux were recorded. In the 2 remaining patients, reflux was measured 16.8% and 55.3% of the total time; however, in both patients, these results were influenced by lengthy bouts of supine reflux. These indices of reflux were not influenced by differences in resting lower esophageal sphincter tone, position, or length. Twenty-four-hour esophageal pH monitoring can be useful in the preoperative assessment of patients with achalasia, and the information obtained might influence the choice of operative procedure.

Pseudocalculus of the common bile duct

Common-bile-duct growths are rarely identified unless they cause chronic biliary obstruction. This case report describes a 71-year-old woman who had jaundice and epigastric pain. A cholecysto-colonic fistula was demonstrated by endoscopic retrograde cholangiopancreatography. The patient also had multiple filling defects in the common bile duct. The fistula was closed and stones were removed. A postoperative cholangiogram showed two calculi. One was removed with a basket through the T-tube tract, but the second, which did not appear completely free of the common-duct wall, could not be removed by the basket method. Subsequently at laparotomy this was found to be a benign pedunculated polyp, composed of collagenous and vascular tissue and with no surface epithelium. Surgeons should bear in mind the possibility of a common-bile-duct growth in cases of extrahepatic biliary obstruction.

Prospective assessment of risk of bacteremia with colonoscopy and polypectomy

A prospective assessment was made of the frequency of positive blood cultures in patients undergoing colonoscopy with or without polypectomy. A total of 270 patients underwent 280 colonoscopies, of these, there were 105 patients that had 111 polypectomies. Blood cultures were taken prior to and within 15 min following each procedure. Six of 280 (2.1%) preprocedural blood cultures were positive. Seven of 169 (4%) blood cultures were positive within 15 min of insertion of the colonoscope in the colonoscopy only group. Eight of 223 (3.6%) blood cultures were positive within 10 min of the polypectomy. There was no clinical evidence of sepsis during the 24 hr following these procedures. In order to determine appropriate postprocedural sampling intervals, we induced a Staphylococcus epidermidis bacteremia with a mean of 1.16 X 10(6) colony forming units/ml on 10 occasions in seven dogs. Within 30 min of inoculation, we were able to detect only one colony forming unit/ml. The rate of positive blood cultures during colonoscopy alone and following polypectomy during colonoscopy is comparable to other gastrointestinal endoscopy procedures. The most optimal time to collect blood cultures in order to detect transient bacteremia is as soon after the procedure as is feasibly possible.

Risk of bacteremia with endoscopic sphincterotomy

A prospective assessment of the risk of bacteremia with endoscopic sphincterotomy was made in 81 patients who underwent 95 procedures. Blood samples were taken for culture in all patients before and at 5 and 10 minutes after the last incision of the sphincter by the papillotome. An additional blood sample was obtained for culture within 30 seconds of the final incision in 32 of the 95 procedures. The rate of blood-culture positivity before the procedure was not significantly different from the post-incisional rate (1% compared with 3%, p greater than 0.05). No patient suffered from fever or chills during the 24 hours after sphincterotomy.

Giant villous adenoma of second portion of duodenum: case report

Villous adenomas of the duodenum are rare. In this report the authors describe the case of a 75-year-old woman who had an extensive adenoma involving the second portion of the duodenum and ampulla of Vater. The patient was successfully managed by a pancreaticoduodenectomy. The authors describe the histopathology of the lesion and suggest guidelines for surgical consideration.

Retrosternal pain subsequent to sclerotherapy

A controlled trial was conducted to determine the etiology of retrosternal pain following sclerotherapy. Sclerotherapy was performed on patients that had previously bled from varices. Esophageal motility studies were recorded from seven patients prior to sclerotherapy and immediately subsequent (within 10 min) to it. Motility studies were also recorded from seven normal subjects before and after undergoing gastroscopy to determine the effects of gastroscopy upon esophageal motility. Sclerotherapy appears to induce a transient pattern of diffuse esophageal spasm, the main features of which are significantly (p less than 0.05) prolonged wave duration, increased peak amplitude, and simultaneous contractions.

Infectious complications of endoscopic injection sclerotherapy

We prospectively assessed the infectious complications of esophageal injection sclerotherapy (EIS) in 38 patients who underwent 104 procedures. Blood cultures were taken prior to and five and ten minutes after injection of the sclerosing agent in all procedures in an attempt to determine the frequency of positive blood cultures. Surveillance cultures were obtained from each patient's pharynx and from the biopsy channel of the endoscope to identify potential sources of bacteremia. The rate of blood culture positivity before injection was not significantly different from that after injection (1.9% vs 4.3%). In only one procedure was the same organism isolated five and ten minutes after sclerotherapy. The isolate in both samples was a Corynebacterium species. Endoscope surveillance cultures were positive prior to 42 of 102 procedures, although none of those organisms subsequently were isolated in the blood cultures. Since the rate of positive blood cultures following EIS is no greater than that before the procedure, the use of prophylactic antibiotics is unnecessary.

Infectious complications of endoscopic retrograde cholangiopancreatography. A prospective assessment

A prospective assessment of the bacterial complications of endoscopic retrograde cholangiopancreatography (ERCP) was made in 97 unselected patients undergoing 101 endoscopies. Blood cultures were taken before and five and ten minutes after completion of the procedure. In an attempt to identify a potential source of infection, aspirates were taken from the pancreaticobiliary duct (PBD) after injection of contrast material. Blood cultures from all procedures were negative. In 14 patients PBD aspirates yielded Pseudomonas aeruginosa, pyocin type 22 and serotype O6, suggesting a common source for this organism. Isolation of this strain ceased after more rigorous cleansing and disinfection of the endoscope. The occurrence of bacteremia following ERCP is low, but there is a risk of transmission of potential nosocomial pathogens with this procedure.

Intestinal villus blood flow measured with carbon monoxide and microspheres

The purpose of the present study was to compare the small intestinal blood flow that equilibrates with luminal CO (FLco) with simultaneous determinations of villus blood flow measured by a recent modification of the microsphere technique. These studies, carried out in rabbits, showed that FLco closely correlated (r = 0.83) with villus flow measured with microspheres over a three-fold range of flows, and the mean rate of flow to the villi by both techniques was about 0.08 ml/min X g of intestine. Thus, FLco appears to be a measure of villus blood flow. Based on previous studies of inert gas uptake from the rabbit small intestine, it appears that absorption of readily diffusible substances in the rabbit can be represented by a simple two-component model: a flow-limited component in which substances equilibrate with villus blood flow and are carried away without subsequent countercurrent exchange, and a diffusion-limited component which presumably represents uptake by the blood flow of the crypt region or submucosa.