Safety of infliximab in Crohn's disease: a large single-center experience

BACKGROUND

The aim of this study was to evaluate the short- and long-term safety experience of infliximab treatment in patients with Crohn's disease (CD) in clinical practice.

METHODS

The medical records of 297 consecutive patients with CD treated with infliximab at the Beth Israel Deaconess Medical Center were reviewed for demographic features and adverse events.

RESULTS

The 297 patients received a total of 1794 infusions. Patients received a median of four infusions and had a median follow-up of 14.3 months. Forty-four patients (15%) experienced a serious adverse event, requiring the infusion to be stopped in 33 patients (11%). Acute infusion reactions occurred in 18 patients (6%) including respiratory problems in 10 patients (3%) and an anaphylactoid reaction in 1 patient (0.3%). Serum sickness-like disease occurred in one patient (0.3%) and three patients (1%) developed drug-induced lupus. One patient developed a probable new demyelination disorder. Eight patients (2.7%), all of whom were on concurrent immunosuppressants, developed a serious infection, one resulting in fatal sepsis. Six patients (2%) developed malignancies including two lymphomas and two skin cancers. A total of four (1.3%) deaths were observed (median age 72.5 years); two due to gastrointestinal bleeding, one due to sepsis, and one due to malignancy.

CONCLUSIONS

While short- and long-term infliximab therapy was generally well tolerated, serious adverse events occurred in 15% of patients including drug-induced lupus, fatal sepsis, and malignancy. Concomitant immunosuppressants were significantly associated with infections and deaths, particularly among elderly patients.

Glucocorticoid resistance in inflammatory bowel disease

Glucocorticoids are potent inhibitors of T cell activation and proinflammatory cytokines and are highly effective treatment for active inflammatory bowel disease (IBD). However, failure to respond, acutely or chronically, to glucocorticoid therapy is a common indication for surgery in IBD, with as many as 50% of patients with Crohn's disease (CD) and approximately 20% of patients with ulcerative colitis (UC) requiring surgery in their lifetime as a result of poor response to glucocorticoids. Studies report that approximately one-third of patients with CD are steroid dependent and one-fifth are steroid resistant while approximately one-quarter of patients with UC are steroid dependent and one-sixth are steroid resistant. While the molecular basis of glucocorticoid resistance has been widely assessed in other inflammatory conditions, the pathophysiology of the glucocorticoid resistance in IBD is poorly understood. Research in IBD suggests that the phenomenon of glucocorticoid resistance is compartmentalised to T-lymphocytes and possibly other target inflammatory cells. This review focuses on three key molecular mechanisms of glucocorticoid resistance in IBD: (i) decreased cytoplasmic glucocorticoid concentration secondary to increased P-glycoprotein-mediated efflux of glucocorticoid from target cells due to overexpression of the multidrug resistance gene (MDR1); (ii) impaired glucocorticoid signaling because of dysfunction at the level of the glucocorticoid receptor; and (iii) constitutive epithelial activation of proinflammatory mediators, including nuclear factor kappa B, resulting in inhibition of glucocorticoid receptor transcriptional activity. In addition, the impact of disease heterogeneity on glucocorticoid responsiveness and recent advances in IBD pharmacogenetics are discussed.

P-glycoprotein-170 inhibition significantly reduces cortisol and ciclosporin efflux from human intestinal epithelial cells and T lymphocytes

AIM

To assess the role of P-glycoprotein-170 (P-gp) in transporting cortisol and ciclosporin from human intestinal epithelium and T lymphocytes.

METHODS

The effect of P-gp inhibitors (verapamil, 0-100 microM; PSC 833, 0-20 microM) on the intracellular accumulation of 3H-cortisol and 3H-ciclosporin was studied in confluent layers of human Caco-2 cells (n=6), a P-gp-dependent absorptive intestinal epithelial cell phenotype, and moderately resistant MDRhigh CEM/VBL 100 T cells (n=6). The transport of 3H-vinblastine, a strong multidrug resistance (MDR) substrate, and 3H-progesterone, a poor MDR substrate, was also studied.

RESULTS

Caco-2 cells had a 2.4-, 6.6-, 6.7- and 1.03-fold higher net basal to apical transport (efflux) of 3H-cortisol, 3H-ciclosporin, 3H-vinblastine and 3H-progesterone, respectively. PSC 833 (20 microM) reduced cortisol efflux by 69% (0.23 +/- 0.04 to 0.07 +/- 0.01 pmol/cm2/h, P < 0.05) and ciclosporin efflux by 76% (11.1 +/- 1.4 to 2.7 +/- 0.6 pmol/cm2/h, P < 0.001). MDRlow CEM T cells had a 1.4-, 1.9-, 3.2- and 1.02-fold higher intracellular accumulation of cortisol, ciclosporin, vinblastine and progesterone than MDRhigh CEM/VBL 100 T cells. Increasing concentrations of PSC 833 (> 0.1 microM) and verapamil (> 1 microM) restored the intracellular level of 3H-cortisol and 3H-ciclosporin in MDRhigh CEM/VBL 100 T cells to that of MDRlow CEM cells with little change in accumulation in the MDRlow parental cell line.

CONCLUSIONS

P-gp inhibitors significantly increase intracellular cortisol and ciclosporin levels in human intestinal epithelium and T lymphocytes in a dose-dependent manner, demonstrating a potential mechanism for overcoming poor response to immunosuppressant therapy in refractory inflammatory bowel disease.

Diagnosis of celiac sprue

Celiac sprue is a common lifelong disorder affecting 0.3-1% of the Western world and causing considerable ill health and increased mortality, particularly from lymphoma and other malignancies. Although high prevalence rates have been reported in Western Europe, celiac sprue remains a rare diagnosis in North America. Whether celiac sprue is truly rare among North Americans or is simply underdiagnosed is unclear, although serological screening of healthy American blood donors suggests that a large number of American celiacs go undiagnosed. Celiac sprue is an elusive diagnosis, and often its only clue is the presence of iron or folate deficiency anemia or extraintestinal manifestations, such as osteoporosis, infertility, and neurological disturbances. The challenge for gastroenterologists and other physicians is to identify the large population of undiagnosed patients that probably exists in the community and offer them treatment with a gluten-free diet that will restore the great majority to full health and prevent the development of complications. The advent of highly sensitive and specific antiendomysium and tissue transglutaminase serological tests has modified our current approach to diagnosis and made fecal fat and D-xylose absorption testing obsolete. A single small bowel biopsy that demonstrates histological findings compatible with celiac sprue followed by a favorable clinical and serological response to gluten-free diet is now considered sufficient to definitely confirm the diagnosis. We review the wide spectrum of celiac sprue, its variable clinical manifestations, and the current approach to diagnosis.

The combination of stricture dilation, endoscopic needle aspiration, and biliary brushings significantly improves diagnostic yield from malignant bile duct strictures

BACKGROUND

Brush cytology, routinely performed at ERCP to assess malignant-appearing biliary strictures, is limited by relatively low sensitivity and negative predictive value. This study assessed whether the combination of stricture dilation, endoscopic needle aspiration, and biliary brushing improves diagnostic yield.

METHODS

In a prospective nonrandomized study, 46 consecutive patients were evaluated with malignant-appearing biliary strictures at ERCP. Twenty-four patients (Group A) underwent standard brush cytology alone and 22 patients (Group B) underwent stricture dilatation to 10F, endoscopic needle aspiration, and subsequent biliary brushing by using the Howell biliary system. The diagnostic yields for both techniques were compared.

RESULTS

Of the 46 patients, 34 had proven malignant strictures (14 Group A, 20 Group B). Compared with brushing alone, the combination of stricture dilatation, endoscopic needle aspiration, and subsequent biliary brushing significantly increased both the sensitivity (57% vs. 85%, p < 0.02) and specificity (80% vs. 100%, p < 0.02) of cytology with positive brushings in all patients with pancreatic or gallbladder carcinoma.

CONCLUSIONS

The combination of stricture dilation, endoscopic needle aspiration, and biliary brushing significantly improves diagnostic yield for malignant bile duct strictures and may particularly be of benefit for extrinsic strictures caused by pancreatic or gallbladder carcinoma.

Development of chronic colitis is dependent on the cytokine MIF

The cytokine macrophage-migration inhibitory factor (MIF) is secreted by a number of cell types upon induction by lipopolysaccharide (LPS). Because colitis is dependent on interplay between the mucosal immune system and intestinal bacteria, we investigated the role of MIF in experimental colitis. MIF-deficient mice failed to develop disease, but reconstitution of MIF-deficient mice with wild-type innate immune cells restored colitis. In addition, established colitis could be treated with anti-MIF immunoglobulins. Thus, murine colitis is dependent on continuous MIF production by the innate immune system. Because we found increased plasma MIF concentrations in patients with Crohn's disease, these data suggested that MIF is a new target for intervention in Crohn's disease.

Vaccines: an ongoing promise?

Over the past decade, intensive research has focused on developing a vaccine therapy for Helicobacter pylori. Substantial unresolved questions cloud the current approach, and the development of a vaccine against this unique organism has proved very challenging. Many candidate vaccines have been tested in animal models. The immunogenicity and the safety of some vaccine formulations have been recently evaluated through clinical trials, and the efficacy of these vaccine therapies in humans will be determined in the near future. This article will provide an overview of the current knowledge of natural and vaccine-induced immune responses to H. pylori infection. It will also review past vaccine successes and failures in animal models and the limited experience to date in using vaccine therapy in humans. Several obstacles to H. pylori vaccine development efforts along with the future direction of these efforts will be discussed.

Clostridium difficile

Clostridium difficile is a major cause of antibiotic-associated diarrhea and colitis. The incidence of infection with this organism is increasing in hospitals worldwide, consequent to the widespread use of broad-spectrum antibiotics. Pathogenic strains of C. difficile produce two protein exotoxins, toxin A and toxin B, that cause colonic mucosal injury and inflammation. Many patients who are colonized are asymptomatic, and recent evidence indicates that diarrhea and colitis occur in those individuals who lack a protective antitoxin immune response. In patients who do develop symptoms, the spectrum of C. difficile disease ranges from mild diarrhea to fulminant pseudomembranous colitis. Prevention of nosocomial C. difficile infection involves judicious use of antibiotics and multidisciplinary infection control measures to reduce environmental contamination and patient cross-infection. Ultimately, active or passive immunization against C. difficile may be an effective means of controlling the growing problem of nosocomial C. difficile diarrhea and colitis.

Potential impact of magnetic resonance cholangiopancreatography on endoscopic retrograde cholangiopancreatography workload and complication rate in patients referred because of abdominal pain

BACKGROUND AND STUDY AIMS

Endoscopic retrograde cholangiopancreatography (ERCP) has a significant mortality, morbidity, and failed cannulation rate. Magnetic resonance cholangiopancreatography (MRCP) is a safer, noninvasive method of imaging the pancreaticobiliary tree. A substantial number of patients are referred for ERCP because of abdominal pain, a high proportion of whom have normal ducts or pathology not requiring interventional ERCP. The aim was to assess the potential impact of MRCP on overall ERCP workload and patient outcome if MRCP were the primary investigation in patients referred for ERCP because of abdominal pain.

PATIENTS AND METHODS

1758 consecutive ERCPs performed in 1148 patients over a 3-year period in a single tertiary referral center in the pre-MRCP era were reviewed. Cannulation failure, ERCP findings, need for follow-up ERCP and all 30-day major complication rates were analyzed with regard to clinical indications.

RESULTS

The overall workload comprised 1108 (63 %) successful initial ERCPs, 188 (11 %) failed cannulation attempts and 462 (26 %) follow-up ERCPs. Of the patients, 299 (27 %) had normal ERCP findings, 331 (30 %) had choledocholithiasis and 246 (22 %) had strictures. lf MRCP had been used as the primary imaging investigation in the 451 patients (39 %) referred for ERCP because of abdominal pain, we estimate that 197 patients (44 %) would have avoided ERCP, and the overall ERCP workload would have been reduced by 13 %. Initial MRCP in suspected gallstone pancreatitis and certain miscellaneous groups, it was estimated, would have further decreased ERCP workload by 9 %. Four of 40 major ERCP-related complications (3.5 %) and one of four ERCP-related deaths (0.35 %) would potentially have been avoided.

CONCLUSIONS

Initial MRCP in patients referred with abdominal pain would potentially have avoided ERCP in 44 % of cases, reduced ERCP workload by 13 % and significantly reduced patient morbidity and mortality. The relatively small reduction in ERCP workload among these patients reflects the fact that over half of them had probable sphincter dysfunction, a significant proportion of whom might have benefited from biliary manometry and/or endoscopic intervention despite a normal MRCP. Furthermore, a small number of patients with calculi and subtle biliary and pancreatic strictures would be missed by this approach.

Diagnostic and therapeutic ERCP: a large single centre's experience

BACKGROUND

Most large published series on endoscopic retrograde cholangiopancreatography (ERCP) are multicentre-based and consequently reflect varying experience.

AIMS

To assess morbidity and mortality rates of ERCP in a single tertiary referral centre.

METHODS

A series of 1,758 consecutive ERCPs performed in 1,148 patients between 1991 and 1994 were reviewed to evaluate indications, findings, procedures, success, complication and mortality rates.

RESULTS

There were 1,108 (63%) successful initial ERCPs, 11% failed cannulation attempts and 26% follow-up ERCPs. The desired duct was successfully cannulated in 96.5% of cases. Initial cannulation failure rate was 8.8%. Twenty-seven per cent had normal ERCPs, 30% had choledocholithiasis and 22% had strictures. Fifty-five per cent had therapeutic ERCPs. Major complications occurred in 3.5% with four ERCP-related deaths (0.35%). Therapeutic ERCP had a higher incidence of major complications compared to diagnostic ERCP: 4.6% vs 2.1%, (p=0.02); and mortality rate was 0.5% vs 0.2%, (p=0.4). Significant haemorrhage secondary to biliary sphincterotomy, pre-cut papillotomy and snare papillectomy accounted for most of the difference (1.6%).

CONCLUSIONS

The majority of ERCPs were performed in elderly patients, over half of whom required therapeutic ERCP. Therapeutic ERCP carried significantly higher complication rate compared with diagnostic ERCP. Unsuccessful cannulation and follow-up ERCP accounted for 11% and 26% of ERCP workload, respectively.

Diverticular disease in the elderly

Diverticular disease is common among the elderly. Because of the advanced age and muted symptoms and signs of many of those affected, diagnosis can be difficult. Consequently, great demands are placed on the physician to diagnose and treat clinically evident diverticular disease. Endoscopic, radiologic, and surgical advances have increased the availability of more definitive therapies for patients with complicated diverticular disease and diverticular hemorrhage.

Gastroenterological causes of pelvic pain

Chronic pelvic pain is a common condition, which accounts for up to 10% of gynecological consultations and for over a third of diagnostic laparoscopies. In addition to gynecological etiologies for the pelvic pain, the physician must also consider gastroenterological, urological, and neurological disease as a possible basis for the pain. This article discusses the major gastroenterological causes of pelvic pain.

State-of-the-art ultrasonography is as accurate as helical computed tomography and computed tomographic angiography for detecting unresectable periampullary cancer

OBJECTIVE

To compare the ability of state-of-the-art ultrasonography with that of helical computed tomography and computed tomographic angiography in detecting unresectable periampullary cancer. In most patients periampullary cancer is unresectable because of either distant metastasis or local vascular involvement. The advent of gray scale and color Doppler ultrasonography has improved the ability of ultrasonography to detect vascular involvement.

METHODS

Twenty-three consecutive patients with periampullary cancer were enrolled for prospective staging of their disease by comparing helical computed tomography and computed tomographic angiography with gray scale and color Doppler ultrasonography of the abdomen. Portal vein, superior mesenteric vein, splenic vein, and superior mesenteric artery involvement was graded 0 to 4, grade 0 being no vascular involvement and grade 4 being total occlusion of the vessel. Agreement between ultrasonography and computed tomographic angiography for determining vascular involvement was measured by chi2 analysis.

RESULTS

Two patients (9%) were excluded because excessive overlying bowel gas hampered the ability of ultrasonography to visualize the pancreas. For the remaining 21 patients, there was significant agreement between ultrasonography and computed tomographic angiography for detecting vascular involvement in all vessels (P < .001; portal vein, kappa = 0.67; superior mesenteric vein, kappa = 0.67; splenic vein, kappa = 0.85; and superior mesenteric artery, kappa = 0.59). Ultrasonography was in agreement with computed tomographic angiography in all cases of unresectability. Both modalities were equally poor in preoperatively showing lymphadenopathy and metastases.

CONCLUSIONS

Provided that there is adequate visualization on ultrasonography of the head of the pancreas in the periampullary region, then state-of-the-art gray scale and color Doppler ultrasonography are as accurate as helical computed tomography and computed tomographic angiography for detecting the unresectability of periampullary cancer. If performed as the initial investigation and the region of the pancreatic head is clearly shown, and if vascular encasement or occlusion or distant metastasis is identified, further investigations are unnecessary.

Recent advances in inflammatory bowel disease

The last decade has seen tremendous advances in our knowledge, which has led to genuine improvements in our understanding of the pathogenesis and management of inflammatory bowel disease (IBD). The combined power of cellular and molecular biology has begun to unveil the enigmas of IBD, and, consequently, substantial gains have been made in the treatment of IBD. Refinements in drug formulation have provided the ability to target distinct sites of delivery, while enhancing the safety and efficacy of older agents. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This article addresses our current understanding of the pathogenesis of IBD, including the latest developments in animal models and covers agents currently used in the treatment of IBD as well as emerging therapies.

Clinical experience with infliximab therapy in 100 patients with Crohn's disease

OBJECTIVE

The aim of this study was to assess our clinical experience with infliximab, a monoclonal antitumor necrosis factor antibody, following its approval for treatment of refractory Crohn's disease (CD).

METHODS

We followed 100 consecutive patients with CD (53 women and 47 men; mean age, 41 yr) who received a total of 233 infliximab (5 mg/kg) infusions. Adverse events were noted and clinical response assessed every 2 wk for 6 months after each infusion using the Harvey Bradshaw Index (HBI) for active disease, the Perianal Disease Activity Index (PDAI) for fistulous disease, and steroid withdrawal rates for steroid-sparing efficacy.

RESULTS

Indications for therapy were active disease (n = 57), perianal fistulous disease (n = 33), and steroid dependency (n = 10). Significant infusion reactions occurred in 16 patients (6.9% of infusions) including anaphylactic shock in one patient. Fourteen patients experienced infectious adverse events, 13 of whom were on concurrent steroids. Sixty percent of patients with active disease experienced > or = 50% HBI reduction at 2 wk; mean duration of response, 8.2 wk. Three of 26 first-time nonresponders with active disease (12%) responded to a second infusion. Sixty-nine percent of patients with fistulous disease experienced >50% reduction in their PDAI at 2 wk; mean duration of response, 10.9 wk. Four of 10 steroid-dependent patients (40%) discontinued steroid therapy, one of whom recommenced steroid therapy at 24 wk.

CONCLUSIONS

Our clinical response rates mirror the efficacy reported in the controlled trials for active and fistulous disease. Steroid-sparing efficacy was seen in 40% of steroid-dependent patients. Concurrent steroids did not reduce the risk of significant infusion reactions (6.9%), but did increase the risk of infections.

Utility of intravenously administered contrast material at CT colonography

PURPOSE

To determine if intravenously administered contrast material improves overall reader confidence in the assessment of the colon, large-bowel wall conspicuity, and diagnostic accuracy in the detection of colorectal polyps and cancers at computed tomographic (CT) colonography.

MATERIALS AND METHODS

Two hundred patients underwent CT colonography in both supine and prone positions. A five-point scale was used to assess the effect of contrast enhancement on overall reader confidence and bowel wall conspicuity. Eighty-one patients underwent CT colonography with complete colonoscopic or surgical correlation; diagnostic accuracy was compared in 48 patients who received contrast material and 33 who did not.

RESULTS

Bowel preparation was ideal in 38 (19%) of 200 patients. Enhanced prone CT images had significantly better scores for reader confidence (4.9 +/- 0.1 vs 4.6 +/- 0.1, P: <.005) and bowel wall conspicuity (4.6 +/- 0.2 vs 4.2 +/- 0.2, P: <.005) compared with those of nonenhanced prone images despite no significant difference in bowel distention (3.8 +/- 0.2 vs 3.9 +/- 0. 1, P: =.8). Enhancement significantly improved the ability to depict medium (6-9-mm) polyps (75% vs 58%, P: <.05). Three large (10-19-mm) polyps were detected only with contrast enhancement; two remained submerged despite dual positioning.

CONCLUSION

The use of intravenously administered contrast material significantly improved reader confidence in the assessment of bowel wall conspicuity and the ability of CT colonography to depict medium polyps in suboptimally prepared colons.

MR cholangiopancreatography of pancreaticobiliary diseases: comparison of single-shot RARE and multislice HASTE sequences

AIMS

We prospectively compared two breath-hold magnetic resonance cholangiopancreatography (MRCP) sequences: single-shot rapid acquisition with relaxation enhancement (RARE) and multislice half-Fourier acquisition single-shot turbo spin echo (HASTE) in imaging the pancreaticobiliary system.

PATIENTS AND METHODS

The diagnostic accuracy of single-shot RARE and multislice HASTE was studied in 34 subjects who had undergone conventional cholangiopancreatography. Overall image quality, duct conspicuity, image artifact, signal intensity and contrast-to-noise ratios were assessed independently by two radiologists who were unaware of the underlying diagnosis.

RESULTS

Both sequences had comparable diagnostic accuracy regarding a normal biliary system, choledocholithiasis, extra-hepatic and intra-hepatic strictures. Single-shot RARE was superior to multislice HASTE in diagnosing a normal pancreatic system, pancreatic and intrahepatic duct strictures, while providing significantly better image quality (mean +/- SE 3.7 +/- 0.07 vs 3.3 +/- 0.08: P = 0.02) and significantly less image artifact (mean +/- SE 3.6 +/- 0.07 vs 3.2 +/- 0.08: P = 0.01). Single-shot RARE provided significantly better duct conspicuity regarding the pancreatic duct within the body (2.7 +/- 0.2 vs 2.1 +/- 0.2: P = 0.003) and tail (2.4 +/- 0.2 vs 1.6 +/- 0.2;P = 0.0001), as well as the intrahepatic ducts (3.0 +/- 0.1 vs 2.6 +/- 0.1: P = 0.004) but there was no significant difference regarding the remainder of the biliary tree.

CONCLUSION

Single-shot RARE provides superior image quality, duct conspicuity with the added advantage of less image artifact and shorter acquisition time. However, volume averaging can cause common bile duct stones to be missed. Therefore, multislice HASTE sequences should still be acquired if choledocholithiasis is suspected. Larger studies are required to assess the diagnostic efficacy of single-shot RARE sequences in pancreatic duct and intra-hepatic duct disease.Morrin, M. M. (2000). Clinical Radiology55, 866-873.

Increased incidence of non-Hodgkin's lymphoma in inflammatory bowel disease patients on immunosuppressive therapy but overall risk is low

BACKGROUND

There is concern that the incidence of non-Hodgkin's lymphoma (NHL) will rise with increasing use of immunosuppressive therapy.

AIMS

Our aim was to determine the risk of NHL in a large cohort of patients with inflammatory bowel disease (IBD), and to study the association between IBD, NHL, and immunosuppressive therapy.

METHODS

We studied 782 IBD patients (238 of whom received immunosuppressive therapy) who attended our medical centre between 1990 and 1999 (median follow up 8.0 years). Standardised incidence ratios (SIRs) and 95% confidence intervals (CI) were calculated. Expected cases were derived from 1995 age and sex specific incidence rates recorded by the National Cancer Registry of Ireland.

RESULTS

There were four cases of NHL in our IBD cohort (SIR 31.2; 95% CI 2.0-85; p=0.0001), all of whom had received immunosuppressive therapy: azathioprine (n=2), methotrexate (n=1), and methotrexate and cyclosporin (n=1). Our immunosuppressive group had a significantly (59 times) higher risk of NHL compared with that expected in the general population (p=0.0001). Three cases were intestinal NHL and one was mesenteric. Mean age at NHL diagnosis was 49 years, mean duration of IBD at the time of NHL diagnosis was 3.1 years, and mean duration between initiation of immunosuppressive therapy and diagnosis of NHL was 20 months.

CONCLUSIONS

Although underlying IBD may be a causal factor in the development of intestinal NHL, our experience suggests that immunosuppressive drugs can significantly increase the risk of NHL in IBD. This must be weighed against the improved quality of life and clinical benefit immunosuppressive therapy provides for IBD patients.

Virtual colonoscopy: a gastroenterologist's perspective

Virtual colonoscopy is an exciting new imaging technique with potential to alter current diagnostic approaches to colonic diseases, particularly colonic neoplasms. Although colonoscopy continues to offer the highest sensitivity and specificity for evaluation of the colon, virtual colonoscopy may offer greater safety, less discomfort, and consequently greater patient acceptance. In addition, virtual colonoscopy offers shorter procedure time, more accurate lesion location, and potentially lower cost as a screening test. Limited data are currently available to define virtual colonoscopy's full clinical role. This article describes the technical considerations, current clinical status, limitations, and potential indications of this new and exciting technology which gastroenterologists should not fear but embrace.

Role of virtual computed tomographic colonography in patients with colorectal cancers and obstructing colorectal lesions

PURPOSE

The aim of this study was to assess the ability of computed tomographic colonography to diagnose colorectal masses, stage colorectal cancers, image the proximal colon in obstructing colorectal lesions, and evaluate the anastomoses in patients with previous colorectal surgery.

METHODS

We prospectively performed computed tomographic colonography examinations in 34 patients (20 males; mean age, 64.2; range, 19-91 years): 20 patients had colorectal masses (defined at endoscopy as intraluminal masses 2 cm or larger), 7 patients had benign obstructing colorectal strictures, and 7 patients had a prior colorectal resection. Final tumor staging was available in all 16 patients who had colorectal cancers and 15 patients were referred after incomplete colonoscopy. The ability of computed tomographic colonography to stage colorectal cancers, identify synchronous lesions in patients with colorectal masses, and image the proximal colon in patients with obstructing colorectal lesions was assessed.

RESULTS

Computed tomographic colonography identified all colorectal masses, but overcalled two masses in patients who were either poorly distended or poorly prepared. Computed tomographic colonography correctly staged 13 of 16 colorectal cancers (81 percent) and detected 16 of 17 (93 percent) synchronous polyps. Computed tomographic colonography over-staged two Dukes Stage A cancers and understaged one Dukes Stage C cancer. A total of 97 percent (87/90) of all colonic segments were adequately visualized at computed tomographic colonography in patients with obstructing colorectal lesions compared with 60 percent (26/42) of segments at barium enema (P < 0.01). Colonic anastomoses were visualized in all nine patients, but in one patient, computed tomographic colonography could not distinguish between local tumor recurrence and surgical changes.

CONCLUSION

Computed tomographic colonography can accurately identify all colorectal masses but may overcall stool as masses in poorly distended or poorly prepared colons. Computed tomographic colonography has an overall staging accuracy of 81 percent for colorectal cancer and is superior to barium enema in visualizing colonic segments proximal to obstructing colorectal lesions.

High multidrug resistance (P-glycoprotein 170) expression in inflammatory bowel disease patients who fail medical therapy

BACKGROUND & AIMS

The multidrug resistance (MDR) gene codes for a drug efflux pump P-glycoprotein 170 (Pgp-170) expressed on the surface of lymphocytes and intestinal epithelial cells. Inflammatory bowel disease (IBD) poorly responsive to medical therapy may relate to MDR expression because glucocorticoids are known Pgp-170 substrates.

METHODS

Using flow cytometry, we measured peripheral blood lymphocyte (PBL) MDR in 153 IBD patients and 50 healthy volunteers, and assessed the relationship between PBL, mucosal intraepithelial lymphocyte (IEL), and mucosal epithelial cell (EC) MDR expression in a further 20 IBD patients and 19 controls.

RESULTS

Compared with controls, PBL MDR was significantly elevated in patients with Crohn's disease who required bowel resection for failed medical therapy (mean +/- SEM, 26.7 +/- 2.8 vs. 11.9 +/- 1.0; P <0.0001) and patients with ulcerative colitis who required proctocolectomy for failed medical therapy (20.3 +/- 2.5 vs. 11.9 +/- 1.0; P = 0.001). PBL MDR remained stable over time and was not influenced by disease activity or glucocorticoid therapy. Both PBL and mucosal MDR expression appeared independent of disease activity, and there was a significant correlation between PBL MDR expression and both IEL expression (r = 0.92; P < 0.0001) and EC expression (r = 0.54; P < 0.001).

CONCLUSIONS

PBL and mucosal MDR expression may play an important role in determining the response of IBD patients to glucocorticoid therapy.

Mesalamine-associated thrombocytopenia

We describe a case of a 25-yr-old woman with ulcerative colitis who developed marked thrombocytopenia during treatment and upon rechallenge with oral mesalamine. In contrast to its parent drug, sulfasalazine, which has often been reported to cause serious blood disorders, particularly agranulocytosis, mesalamine has rately been implicated as a cause of serious blood disorders. Although previous cases of hematological toxicity have been described in patients taking mesalamine, none of these patients were rechallenged in an effort to prove causality between 5-aminosalicyclic acid and the hematological abnormality as well as outrule the possible "autoimmune" contribution of inflammatory bowel disease to the hematological toxicity of these agents. This report demonstrates that mesalamine has the potential, like sulphasalazine, to cause marked thrombocytopenia in an idiosyncratic fashion. All patients receiving mesalamine therapy, either orally or topically should have regular, complete blood profiles.

Radiation exposure of the families of outpatients treated with radioiodine (iodine-131) for hyperthyroidism

Patients who receive radioiodine (iodine-131) treatment for hyperthyroidism (195-800 MBq) emit radiation and represent a potential hazard to other individuals. Critical groups amongst the public are fellow travellers on the patient's journey home from hospital and members of the patient's family, particularly young children. The dose which members of the public are allowed to receive as a result of a patient's treatment has been reduced in Europe following recently revised recommendations from ICRP. The annual public dose limit is 1 mSv, though adult members of the patient's family are allowed to receive higher doses, with the proviso that a limit of 5 mSv should not be exceeded over 5 years. Unless the doses received during out-patient administration of radioiodine can be demonstrated to comply with these new limits, hospitalisation of patients will be necessary. The radiation doses received by family members (35 adults and 87 children) of patients treated with radioiodine at five UK hospitals were measured using thermoluminescent dosimeters mounted in wrist bands. Families were given advice (according to current practice) from their treatment centre about limiting close contact with the patient for a period of time after treatment. Doses measured over 3-6 weeks were adjusted to give an estimate of values which might have been expected if the dosimeters had been worn indefinitely. Thirty-five passengers accompanying patients home after treatment also recorded the dose received during the journey using electronic (digital) personal dosimeters. For the "adjusted" doses to infinity, 97% of adults complied with a 5-mSv dose limit (range:0.2-5.8 mSv) and 89% of children with a 1-mSv limit (range: 0.2-7.2 mSv). However 6 of 17 children aged 3 years or less had an adjusted dose which exceeded this 1 mSv limit. The dose received by adults during travel was small in comparison with the total dose received. The median travel dose was 0.03 mSv for 1 h travel (range: 2 microSv-0.52 mSv for 1 h of travel time). These data suggest that hyperthyroid patients can continue to be treated with radioiodine on an out-patient basis, if given appropriate radiation protection advice. However, particular consideration needs to be given to children aged 3 years or younger. Admission to hospital is not warranted on radiation protection grounds.

Guided versus blind liver biopsy for chronic hepatitis C: clinical benefits and costs

BACKGROUND/AIMS

Our objectives were: (1) to assess the clinical benefits and costs of performing ultrasound-guided liver biopsy with an automated needle compared to blind biopsy with a conventional Trucut needle in patients with chronic hepatitis C; (2) to compare the histological yield of automated needles with Trucut needles.

METHODS

We prospectively studied 166 patients with hepatitis C virus who underwent either ultrasound-guided biopsy using automated ASAP needles or blind biopsy using conventional Trucut needles. Both groups were matched for age, sex, cirrhosis, needle gauge and operator experience. Patient tolerance, complications and histological adequacy were assessed. In a separate in vitro study, we assessed the histological adequacy of liver biopsy specimens obtained using automated and Trucut needles from 10 fresh autopsy cases.

RESULTS

Ultrasound-guided biopsy caused significantly less biopsy pain (36.4% vs. 47.3%; p < 0.0001) and significantly less pain-related morbidity (1.8% vs. 7.7%, p < 0.05). Although, there was no significant difference in diagnostic yield between guided and blind biopsy (98% vs. 94%, p = 0.15), 3 blind biopsies (3.3%), including 2 which yielded extra-hepatic tissue, had to be repeated. The additional expense of performing guided liver biopsy with automated needles was 42 Irish Pounds per patient. In vitro, automated ASAP 15G needles provided liver specimens comparable to Trucut 15G needles and had the highest histopathologic score among the automated needles assessed.

CONCLUSIONS

Even in the absence of major complications, ultrasound-guided liver biopsy with an automated needle in HCV patients is safer, more comfortable and only marginally more expensive than blind Trucut biopsy.

Endoluminal CT colonography after an incomplete endoscopic colonoscopy

OBJECTIVE

We evaluated the clinical usefulness of endoluminal CT colonography after an incomplete colonoscopy.

SUBJECTS AND METHODS

We prospectively studied 40 patients in whom the cecum could not be reached endoscopically despite adequate bowel preparation. Endoluminal CT colonography (120 kVp, 120 mA, 3-mm collimation, pitch of 2, 1.5-mm interval reconstruction) was performed within 2 hr of incomplete colonoscopy. Two-dimensional multiplanar reformatted images and three-dimensional endoluminal images were analyzed. Twenty-six patients (65%) underwent barium enema immediately after endoluminal CT colonography. We analyzed colonic distention; duration of endoluminal CT colonography; patient tolerance; number of colonic segments seen at colonoscopy, endoluminal CT colonography, and barium enema; and reasons for incomplete colonoscopy as well as colonic and extracolonic findings.

RESULTS

Duration of endoluminal CT colonography was 14.2 +/- 4.6 min (mean +/- SD). Endoluminal CT colonography was better tolerated than colonoscopy or barium enema (p < .001). Probable causes for incomplete colonoscopy were identified at endoluminal CT colonography in 74% of 40 patients. Baseline colonic distention in the region of the transverse and right colon was considered adequate before additional air insufflation; however, the addition of air significantly enhanced colonic distention throughout the entire colon (p < .001). Endoluminal CT colonography adequately revealed 96% of all colonic segments; in comparison, barium enema adequately revealed 91% of all segments (p < .05).

CONCLUSION

In patients with incomplete colonoscopy, endoluminal CT colonography successfully showed the previously unrevealed colon in more than 90% of patients. Endoluminal CT colonography is a rapid, well-tolerated technique that provides clinically useful colonic and extracolonic information and should be considered for all patients who undergo incomplete colonoscopy.

Endoscopic papillectomy: a novel approach to difficult cannulation

BACKGROUND

Selective cannulation of the biliary and pancreatic ducts is considered to be the most difficult and rate limiting aspect of diagnostic endoscopic retrograde cholangiopancreatography (ERCP).

AIMS/METHODS

A novel technique for difficult cannulation is described and its potential role in relieving malignant duodenal obstruction secondary to ampullary carcinoma. A diagnostic endoscopic papillectomy was performed in 10 patients in whom previous attempts at cannulation had failed. Five patients had exophytic ampullary carcinomas, one had carcinoma of the head of pancreas, two had an oedematous ampulla secondary to low common bile duct stones, while two had protuberant ampullae with ectopic orifices. The technique entails snaring the ampulla flush with the duodenal wall using a polypectomy snare and in a similar fashion to polypectomy removing the ensnared ampulla with diathermy using a coagulation current. The underlying exposed ducts can then be cannulated while the ensnared ampulla can be retrieved to aid histological diagnosis.

RESULTS

Successful cannulation was achieved in all 10 cases with significant haemorrhage in one patient (10%). Four of the snared ampullary carcinomas (80%) were retrieved enabling a histological diagnosis to be made.

CONCLUSIONS

This study demonstrates the potential role for endoscopic papillectomy as a means of cannulation in difficult circumstances, however larger comparative studies are required.

Operative strategies in pancreatic trauma

Pancreatic injuries are relatively uncommon and the choice of an appropriate operative procedure can be difficult. Operations for pancreatic trauma from January 1990 to June 1993 have been reviewed. Fifty-one patients were studied; 13 had blunt trauma, 17 gunshot wounds and 21 stab wounds. The distribution of injuries was: pancreatic head (17), body (15) and tail (19). Most patients had associated injuries of surrounding organs. Operations performed included pancreatoduodenectomy (seven), distal pancreatectomy (seven) and external drainage (35). Five patients (10 per cent) died: two from haemorrhage, one from an acute subdural haematoma and two from multiple organ failure. Ten patients (20 per cent) developed a pancreatic fistula, four following blunt trauma, four after gunshot wounds and two with stab wounds; all but one had undergone drainage procedures. Stab wounds were associated with a low incidence of duct injury and external drainage was usually satisfactory. After blunt trauma and gunshot wounds, duct injuries were common and easily missed; careful exploration by an experienced surgeon is essential. In appropriately selected patients, pancreatic resection can be performed with good result.

Carcinoma of the ampulla of Vater: a tumour with a poor prognosis?

OBJECTIVE

To assess the overall prognosis of patients with ampullary carcinomas and evaluate the presentation, diagnosis, pathology and management of these potentially highly curable tumours, attempting to relate these factors to overall survival.

PATIENTS AND METHODS

Forty patients with ampullary carcinoma were reviewed. Age, Sex, nature and duration of history, laboratory information at admission, results of diagnostic radiology, endoscopic retrograde cholangiopancreatograms and pathological findings were considered. Both curative and palliative management strategies were reviewed.

RESULTS

The overall median survival was 19 months. The median duration of history was 5.9 +/- 5.4. weeks, with no significant difference in survival between patients with short and those with long histories (P = 0.46). Twenty nine (73%) patients were potentially resectable, but only 15 (37%) underwent potentially curative surgery. The difference in survival between the Whipple's (13) and the endoscopically stented (20 ) groups was not significant (p = 0.08). The Whipple's group were significantly younger than the stented group (P = 0.001) and had a significant operative morbidity, re-operation rate (38%) and post-operative mortality (15%). Only five of 13 patients were alive following Whipple's treatment after a mean follow-up of 18.9 months. Sphincterotomy before Whipple's treatment improved survival significantly (P = 0.04); absence of jaundice, exophytic macroscopic appearance, well-differentiated tumours and early stage were also associated with good survival. Endoscopic retrograde cholangiopancreatography has a high diagnostic yield and a low associated morbidity and mortality, with endoscopic papillectomy aiding cannulation while effective palliation was provided through stenting, endoscopic papillectomy and laser debulking of obstructing tumours. Little benefit was obtained from chemoradiotherapy.

CONCLUSION

Despite the potential for curative resection in patients with ampullary carcinoma, the majority of such patients are unsuitable for curative surgery on grounds of age, general health status or advanced disease; since only 37% of patients undergo potentially curative surgery the condition has a poor prognosis.