Neoterminal ileal blood flow after ileocolonic resection for Crohn's disease

Mesenteric-based surgery for Crohn's disease: evidence and perspectives

Postoperative anastomotic recurrence of Crohn's disease is challenging and can lead to symptom recurrence and further surgery. The mesenteric pole of the intestine is the initial site of macroscopic anastomotic recurrence, and the mesentery may play an important role in recurrence after surgical resection. Therefore, "mesenteric-based surgery" has gained increasing attention by clinicians. However, the role of mesentery in the postoperative recurrence remains controversial. This review will examine mesenteric changes in Crohn's disease, proposed roles for mesentery in disease progression, and the potential for mesenteric-based surgery in the surgical management of Crohn disease.

Perfusion Computed Tomography May Help in Discriminating Gastrointestinal Tuberculosis and Crohn’s Disease

Gastrointestinal tuberculosis (GITB) and Crohn’s disease (CD) are close mimics. This prospective study aimed to evaluate the diagnostic performance of perfusion computed tomography (CT) in differentiating GITB from CD. Consecutive patients with ileocaecal thickening underwent perfusion CT of the ileocaecal region between January 2019 and July 2020. Two radiologists (blinded to the final diagnosis) independently assessed blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability at perfusion CT. These parameters were compared among the patients with GITB as well as active and inactive CD. Receiver operating characteristic curves were utilized for determining the diagnostic performance of perfusion CT. Interclass correlation coefficient and Bland–Altman analysis were performed to compare the observations of the two radiologists. During the study period, 34 patients underwent perfusion CT. Eight patients had diagnoses other than intestinal tuberculosis or CD. Thus, 26 patients (mean age 36 ± 14 years, 18 males) with GITB (n = 11), active CD (n = 6), and inactive CD (n = 9) were evaluated. BF, MTT, and permeability showed significant differences among the groups, while BV did not differ significantly among the groups. BF and permeability had 100% sensitivity and 100% specificity, while MTT had 61.5–100% sensitivity and 70–100% specificity for differentiating GITB from active CD and active from inactive CD. The interclass correlation coefficient for perfusion CT parameters was 0.88–1. Perfusion CT is a novel imaging technique that can improve the diagnostic performance of differentiating tuberculosis from CD.

SupportiNg operAtive Photographic documentation in ileocolonic CROHN's disease surgery: The SNAPCROHN study

BACKGROUND

There are reported variations in the intraoperative management of Crohn's disease. This consensus statement aimed to develop a standardised protocol for photographic documentation of intraoperative findings and critical procedural steps in ileocolonic Crohn's disease surgery.

METHODS

Colorectal surgeons with a specialist interest in minimally invasive surgery and inflammatory bowel disease were invited as committee members to develop a survey on the use of photo-documentation in Crohn's disease surgery. A 15 item survey was developed on ethical considerations and applications of photo-documentation in audit and quality control, research, and training.

RESULTS

There was strong agreement on the potential application of intraoperative photo-documentation in Crohn's disease for training, research, quality control and tertiary referrals. Reviewers agreed that intraoperative staging required photo-documentation of strictures, skip lesions, perforations, fat wrapping and mesenteric disease. The necessary steps to be photo-documented were very specific to Crohn's disease surgery, such as views of anastomosis and strictureplasties, and extent of resection(s).

CONCLUSIONS

Our consensus statement identified several items for appropriate intraoperative photo-documentation in Crohn's disease surgery, to be used as an adjunct to accurate annotation of intraoperative findings and procedures.

Anastomotic Considerations in Crohn's Disease

A number of factors should be considered when performing an intestinal anastomosis in the setting of surgery for Crohn's disease. Preoperative risk factors, such as malnutrition, abdominal sepsis, and immunosuppressive medications, may increase the risk of postoperative anastomotic complications and alter surgical decision-making. The anatomical configuration and technique of constructing the anastomosis may have an impact on postoperative function and risk of recurrence, particularly in the setting of ileocolic resection, where the Kono-S anastomosis has gained popularity in recent years. There may be circumstances in which it may be more appropriate to perform an ostomy either without an anastomosis or to temporarily divert an anastomosis when the risk of anastomotic complications is felt to be high. In the setting of total abdominal colectomy or proctocolectomy for Crohn's colitis, restorative procedures may appropriate in lieu of a permanent stoma in certain scenarios.

Altered Bioavailability and Pharmacokinetics in Crohn's Disease: Capturing Systems Parameters for PBPK to Assist with Predicting the Fate of Orally Administered Drugs

Backgrond and Objective

Crohn’s disease (CD) is a chronic inflammatory bowel disease that affects a wide age range. Hence, CD patients receive a variety of drugs over their life beyond those used for CD itself. The changes to the integrity of the intestine and its drug metabolising enzymes and transporters (DMETs) can alter the oral bioavailability of drugs. However, there are other changes in systems parameters determining the fate of drugs in CD, and understanding these is essential for dose adjustment in patients with CD.

Methods

The current analysis gathered all the available clinical data on the kinetics of drugs in CD (by March 2021), focusing on orally administered small molecule drugs. A meta-analysis of the systems parameters affecting oral drug pharmacokinetics was conducted. The systems information gathered on intestine, liver and blood proteins and other physiological parameters was incorporated into a physiologically based pharmacokinetic (PBPK) platform to create a virtual population of CD patients, with a view for guiding dose adjustment in the absence of clinical data in CD.

Results

There were no uniform trends in the reported changes in reported oral bioavailability. The nature of the drug as well as the formulation affected the direction and magnitude of variation in kinetics in CD patients relative to healthy volunteers. Even for the same drug, the reported changes in exposure varied, possibly due to a lack of distinction between the activity states of CD. The highest alteration was seen with S-verapamil and midazolam, 8.7- and 5.3-fold greater exposure, respectively, in active CD patients relative to healthy volunteers. Only one report was available on liver DMETs in CD, and indicated reduced CYP3A4 activity. In a number of reports, mRNA expression of DMETs in the ileum and colon of CD patients was measured, focussing on P-glycoprotein (p-gp) transporter and CYP3A4 enzyme, and showed contradictory results. No data were available on protein expression in duodenum and jejunum despite their dominant role in oral drug absorption.

Conclusion

There are currently inadequate dedicated clinical or quantitative proteomic studies in CD to enable predictive PBPK models with high confidence and adequate verification. The PBPK models for CD with the available systems parameters were able to capture the major physiological influencers and the gaps to be filled by future research. Quantification of DMETs in the intestine and the liver in CD is warranted, alongside well-defined clinical drug disposition studies with a number of index drugs as biomarkers of changes in DMETs in these patients, to avoid large-scale dedicated studies for every drug to determine the effects of disease on the drug’s metabolism and disposition and the consequential safety and therapeutic concerns.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40262-022-01169-4.

Surgical Treatment for Crohn's Disease: A Role of Kono-S Anastomosis in the West

More than 80% of patients with Crohn's disease (CD) will require surgical intervention during their lifetime, with high rates of anastomotic recurrence and stenosis necessitating repeat surgery. Current data show that pharmacotherapy has not significantly improved the natural history of postoperative clinical and surgical recurrence of CD. In 2003, antimesenteric hand-sewn functional end-to-end (Kono-S) anastomosis was first performed in Japan. This technique has yielded very desirable outcomes in terms of reducing the incidence of anastomotic surgical recurrence. The most recent follow-up of these patients showed that very few had developed surgical recurrence. This new approach is superior to stapled functional end-to-end anastomosis because the stumps are sutured together to create a stabilizing structure (a "supporting column"), serving as a supportive backbone of the anastomosis to help prevent distortion of the anastomotic lumen due to disease recurrence and subsequent clinical symptoms. This technique requires careful mesenteric excision for optimal preservation of the blood supply and innervation. It also results in a very wide anastomotic lumen on the antimesenteric side. The Kono-S technique has shown efficacy in preventing surgical recurrence and the potential to become the new standard of care for intestinal CD.

Ex vivo model for a new bilateral antimesenteric V-modified side-to-side isoperistaltic anastomosis to prevent recurrence in ileocolic Crohn's disease

INTRODUCTION

The high rate of recurrence following ileocaecal resection for Crohn's disease may lead to repeat surgery in 20-30% of patients at five years after surgery. Recurrence usually occurs at the anastomosis and the neoterminal ileum and the association of a strictureplasty to widen the bowel lumen in the regions immediately proximal ('anastomotic inlet') and distal ('anastomotic outlet') to the anastomosis may delay or reduce the risk of surgical recurrence.

MATERIALS AND METHODS

A side to side isoperistaltic anastomosis, with an associated V-modified strictureplasty on the anti-mesenteric border at the level of the anastomosis inlet and outlet has been designed. We produced a wet lab ex vivo model of the anastomosis and, to evaluate the different calibre of the anastomotic segments, we compared it with ex vivo models of three anastomotic configurations currently used in surgery for Crohn's disease: i) side to side isoperistaltic anastomosis; ii) modified side-to-side isoperistaltic anastomosis with double Heineke-Mikulicz procedure (Sasaki anastomosis); iii) anti-mesenteric functional end-to-end handsewn anastomosis (Kono-S anastomosis).

RESULTS

Differences were recorded at the level of the anastomosis inlet and outlet, with a larger volume estimated in the Sasaki anastomosis and in the V-modified anastomosis. The V-modified anastomosis had a larger volume compared with the Sasaki anastomosis for a longer segment of small bowel.

CONCLUSIONS

We have developed an experimental animal model for a new anastomotic technique which could be applied in surgery for Crohn's disease following small-bowel or ileocolic resection.

Misbalance in type III collagen formation/degradation as a novel serological biomarker for penetrating (Montreal B3) Crohn's disease

BACKGROUND

Misbalances in extracellular matrix turnover are key factors in the development of stricturing (Montreal B2) and penetrating (Montreal B3) Crohn's disease.

AIM

To determine whether serological markers for collagen formation and degradation could serve as biomarkers for complications of Crohn's disease.

METHODS

Serum biomarkers for type I, III, V and VI collagen formation (P1NP, Pro-C3, Pro-C5, Pro-C6) and matrix metalloproteinase mediated degradation (C1M, C3M, C5M and C6M) were measured in a retrospective, single centre cohort of 112 patients with Crohn's disease in the terminal ileum (nonstricturing/nonpenetrating: n=40, stricturing: n=55, penetrating: n=17) and 24 healthy controls. Active inflammation was defined as CRP >5 mg/L.

RESULTS

C3M and Pro-C5 levels were higher in penetrating vs nonpenetrating/nonstricturing and stricturing disease (33.6±5 vs 25.8±2.2 [P=.004] and 27.2±2.3 [P=.018] nmol/L C3M, 1262.7±259.4 vs 902.9±109.9 [P=.005] and 953.0±106.4 [P=.015] nmol/L Pro-C5). C1M (71.2±26.1 vs 46.2±6.2 nmol/L [P<.001]), C3M (31.6±3.9 vs 26.1±1.6 nmol/L [P=.002] and Pro-C5 levels (1171.7±171.5 vs 909.6±80.4 nmol/L [P=.002]) were higher in patients with active inflammation vs without active inflammation. Pro-C3/C3M-ratios were best to differentiate between penetrating vs nonstricturing/nonpenetrating and stricturing disease with area under the curves of 0.815±0.109 (P<.001) and 0.746±0.114 (P=.002) respectively.

CONCLUSIONS

Serological biomarkers show that penetrating Crohn's disease is characterised by increased matrix metalloproteinase-9 degraded type III collagen and formation of type V collagen. Active inflammation in Crohn's disease is characterised by increased formation of type V collagen and increased matrix metalloproteinase mediated breakdown of type I, III collagen. Pro-C3/C3M ratios are superior in differentiating between penetrating Crohn's disease vs inflammatory and stricturing Crohn's disease.

Identification of the distinguishing features of Crohn's disease and ischemic colitis using computed tomographic enterography

Background and aims: The differential diagnosis between Crohn’s disease (CD) and ischemic colitis (ISC) is important as their clinical management is different. ISC can easily be misdiagnosed as CD, especially in elderly populations. The distinctive radiographic features of the two disease entities have not been investigated. The aim of this study is to assess the utility of computed tomographic enterography (CTE) in the differential diagnosis between CD and ISC.

Methods: Patients with confirmed CD and ISC were identified through an electronic medical record search of the Cleveland Clinic Foundation. Patients who had undergone CTE, with or without concurrent colonoscopy and histopathological specimens, were included in this study. CTE images were blindly re-reviewed by an expert gastrointestinal radiologist. The sensitivities, specificities, accuracies and positive and negative predictive values for each of the CTE findings in differentiating CD from ISC were estimated. Kappa coefficients (κ) were calculated to measure diagnosis agreement between CTE and the reference standard.

Results: A total of 34 eligible patients were included in this study with 17 having CD and 17 having ISC. In differentiating CD from ISC, the presence of mucosal hyperenhancement and absence of the “target sign” on CTE showed a sensitivity of 100% each for CD, while the two radiographic features yielded a low specificity of 35.3% and 76.5%, respectively. The presence of stricture had a lower sensitivity of 64.7% for the detection of CD but had a high specificity of 100%. In distinguishing CD from ISC, the accuracy of presence of mucosal hyperenhancement, stricture and absence of target sign were 67.7%, 82.4% and 88.2%, respectively. The combination of the presence of mucosal hyperenhancement and the absence of the target sign achieved an accuracy of 100% for distinguishing CD from ISC. There was a good correlation between CTE and the reference standard for distinguishing CD from ISC (κ = 0.882).

Conclusions: CTE appeared to be clinically useful in distinguishing CD from ISC.

Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis

Background

The aim of the study was to investigate preventive effects of glutamine (Gln), omega-3 fatty acids (FA) on erythrocyte deformability (EDEF) in rat model of indomethacin-induced enterocolitis.

Methods

Nineteen Wistar albino male rats were divided into three groups: control group, colitis induced by indomethacin and were fed with a standard laboratory diet (group 1), and colitis induced by indomethacin and were also fed with Gln, omega-3 FA (group 2). An investigation was performed in a rat model of experimental colitis induced by subcutaneous injections of 2 mL intdomethacine solution applied at 24 and 48 hours intervals to male Wistar rats for 14 days. Gln and omega-3 FA were added to the daily standard diets of the animals during 14 days of injections. During the study, changes in body weight were evaluated. The intestines were examined, and colitis was macroscopic and histologically scored. The circulating tumor necrosis factor alpha (TNF-α) and interleukine-1β (IL-1β), erythrocyte transit time (ETT) and thiobarbituric acid reactive substances (TBARS) levels were determined in addition to calculation of EDEF indices in all groups.

Results

No significant differences in body weight changes could be determined between the standard diet and special diet groups at the end of the experiment. After macroscopic and microscopic scoring, in all of the groups that colitis was found induced, the lowest microscopic score was observed in the group 2. But Gln and omega-3 FA supplemented diet did not change the mean macroscopic and histological scores in all rats. The proliferating cell nuclear antigen (PCNA) levels were significantly higher in group 1 and group 2 compared to the control group. Effects of the diet on circulating TNF-α and IL-1β levels were found correlated with inflammation but statistically significant differences were not found in the group 1 and group 2 (P < 0.05). The ETT and TBARS levels in standard and special diet groups were significantly increased (P < 0.05). However, EDEF indices which are an important parameter of the study were decreased in indomethacin-induced enterocolitis groups that fed with standard and special diet.

Conclusions

Increases in ETT and TBARS levels did not return to normal by addition of Gln and omega-3 FA to diet. Our results suggest that determination of effective optimal doses and route of administration for these nutrients may play an important role in reducing EDEF and microvascular changes.

Particularities of Crohn's disease in pediatric patients: current status and perspectives regarding imaging modalities

A consensus on the best imaging modality evaluating inflammatory bowel disease in the pediatric population is lacking and it is often unclear which modality to choose in specific clinical circumstances. Children with inflammatory bowel disease are exposed to ionizing radiation from multiple imaging studies performed at initial diagnosis, throughout treatment and during the follow-up period. This paper discusses the value of different imaging techniques in pediatric patients with inflammatory bowel disease and gives a review of the literature. In addition, particular features of inflammatory bowel disease in children including the predilection of affected segments in the gastrointestinal tract are highlighted. Based on current literature knowledge, we encourage an integrative approach to the interpretation of clinical and imaging data for diagnosis and follow-up in daily clinical settings.

Kono-S Anastomosis for Surgical Prophylaxis of Anastomotic Recurrence in Crohn's Disease: an International Multicenter Study

INTRODUCTION

The Kono-S (antimesenteric functional end-to-end handsewn) anastomosis has been used for Crohn's disease in Japan and the USA since 2003 and 2010, respectively. This technique was designed to reduce the risk of anastomotic surgical recurrence. This study reviews the outcomes a decade after the introduction of the Kono-S anastomosis to clinical practice.

METHODS

This study was conducted at five hospitals (four in Japan and one in the USA). A total of 187 patients in Japan (144 patients, group J) and the USA (43 patients, group US) who underwent Kono-S anastomosis for Crohn's disease between September 2003 and September 2011 were included.

RESULTS

With a median follow-up of 65 months, two surgical anastomotic recurrences have occurred in group J. Kaplan-Meier analysis showed that 5 and 10 years surgical recurrence-free survival rate was 98.6% in group J. No surgical anastomotic recurrences have been detected in group US with a median follow-up of 32 months. The Kono-S anastomosis was technically feasible and performed in all patients.

CONCLUSION

The Kono-S anastomosis appears to be safe and effective in reducing the risk of surgical recurrence in Crohn's disease.

Evidence against a systemic arterial defect in patients with inflammatory bowel disease

BACKGROUND

Despite increasing interest in local microvascular alterations associated with inflammatory bowel disease (IBD), the potential contribution of a primary systemic vascular defect in the etiology of IBD is unknown. We compared reactivity of large diameter mesenteric arteries from segments affected by Crohn disease (CD) or ulcerative colitis (UC) to an uninvolved vascular bed in both IBD and control patients.

METHODS

Mesenteric and omental arteries were obtained from UC, CD, and non-IBD patients. Isometric arterial contractions were recorded in response to extracellular potassium (K(+)) and cumulative additions of norepinephrine (NE). In addition, relaxation in response to pinacidil, an activator of adenosine triphosphate-sensitive K(+) channels was examined.

RESULTS

Contraction to K(+) and sensitivity to NE were not significantly different in arteries from CD, UC, and controls. Relaxation to pinacidil was also similar between groups.

CONCLUSIONS

Potassium-induced contractions and sensitivity to NE and pinacidil were not significantly different in large diameter mesenteric and omental arteries obtained from IBD patients. Furthermore, there was no significant difference in the sensitivity to K(+), NE, and pinacidil between mesenteric and omental arteries of CD and UC patients and those from non-IBD patients. Our results suggest an underlying vascular defect systemic to CD or UC patients is unlikely to contribute to the etiology of IBD.

Daikenchuto, a traditional Japanese herbal medicine, ameliorates postoperative ileus by anti-inflammatory action through nicotinic acetylcholine receptors

BACKGROUND

Daikenchuto (DKT), a gastrointestinal prokinetic Japanese herbal medicine, is prescribed for patients with postoperative ileus (POI) and adhesive bowel obstruction following abdominal surgery. Several mechanisms for the amelioration of POI by DKT have been suggested; however, it has remained unclear whether DKT shows anti-inflammatory effects in POI. In the present study, we investigated the effects of DKT in a mouse POI model and attempted to clarify the detailed mechanisms of action.

METHOD

Intestinal manipulation (IM) was applied to the distal ileum of mice. DKT was administered orally to the animals 4 times before and after IM. Gastrointestinal transit in vivo, leukocyte infiltration, cytokine mRNA expression and gastrointestinal motility were analyzed. We also investigated the effects of the α7nAChR antagonist methyllycaconitine citrate (MLA) on the DKT-mediated ameliorative action against POI, and we studied the effects of DKT on inflammatory activity in α7nAChR knockout mice.

RESULTS

DKT treatment led to recovery of the delayed intestinal transit induced by IM. DKT significantly inhibited the infiltration of neutrophils and CD68-positive macrophages, and inhibited mRNA expressions of TNF-α and MCP-1. MLA significantly reduced the anti-inflammatory action of DKT, and the amelioration of macrophage infiltration by DKT was partially suppressed in α7nAChR knockout mice.

CONCLUSIONS

In conclusion, in addition to the gastrointestinal prokinetic action, DKT serves as a novel therapeutic agent for POI characterized by its anti-inflammatory potency. The DKT-induced anti-inflammatory activity may be partly mediated by activation of α7nAChR.

Assessment of wall inflammation and fibrosis in Crohn's disease: value of T1-weighted gadolinium-enhanced MR imaging

MRI is increasingly advocated as a robust method for quantifying disease activity in Crohn's disease. In particular, T1-weighted gadolinium-enhanced imaging shows considerable promise as a marker of inflammatory activity. However, interpretation of the literature must be made with an understanding of (i) the technical limitations of T1-weighted acquisition protocols and enhancement measurements; (ii) differences in standards of reference for disease activity employed between published studies; and (iii) important underlying macro and micro vascular changes in Crohn's disease. This review will focus specifically on the value of T1-weighted gadolinium-enhanced imaging in the assessment of wall inflammation and fibrosis.

Crohn's disease activity: quantitative contrast-enhanced ultrasound assessment

OBJECTIVES

To determine whether quantitative parameters from contrast-enhanced ultrasound examination (CE-US) of the bowel wall correlate with endoscopic inflammatory activity in Crohn's disease and to assess its utility in the follow-up of patients on treatment.

METHODS

This was a prospective study of 30 patients with Crohn's disease requiring colonoscopy or flexible sigmoidoscopy. The Crohn's disease activity index (CDAI), serum C-reactive protein (CRP) and Crohn's disease endoscopic index of severity (CDEIS) were calculated. CE-US was performed within 7 days of endoscopy using intravenous perflutren lipid microsphere and repeated a median of 45.5 days following treatment. Time-intensity curves of bowel wall enhancement were generated to derive the area under the curve (AUC), time to peak intensity (TTP) and peak intensity (PI).

RESULTS

In separate multivariate regression models, the AUC, TTP and PI showed no significant association with endoscopic activity whilst controlling for CDAI and CRP. However, the reductions in CDAI and CRP following treatment were mirrored by significant reductions in TTP (P = 0.05).

CONCLUSIONS

CE-US does not appear to predict for Crohn's disease endoscopic activity independent of simple parameters such as CDAI and CRP. However, it may be useful in the serial assessment of patients on treatment.

Antimesenteric functional end-to-end handsewn (Kono-S) anastomosis

INTRODUCTION

Anastomotic recurrence is a frequent event after bowel resection for Crohn's disease. To date, no anastomotic technique has been proven to be superior in reducing surgical recurrence rates in this setting. In this article, we describe our technique in performing a new antimesenteric functional end-to-end handsewn (Kono-S) anastomosis.

METHODS

The segment of bowel to be resected is identified and mobilized. The bowel is then divided transversely with a linear stapler-cutter device. The intervening mesentery is divided close to the bowel. The corners of the two stapled lines are sutured together, and the two stapled lines are approximated with interrupted sutures. An antimesenteric longitudinal enterotomy is performed on both sides, starting no more than 1 cm away from the staple line, to allow a transverse lumen of 7-8 cm. The openings are closed transversely in two layers.

RESULTS

From May 1, 2010 to July 31, 2011 we performed 46 Kono-S anastomoses. One patient had a contained anastomotic leak successfully treated conservatively. Currently, 18 patients (43 %) have undergone follow-up endoscopic surveillance with an average Rutgeert's score of 0.7 (0-3) at a mean of 6.8 months.

CONCLUSION

The Kono-S anastomosis is a safe anastomotic technique. Long-term studies are needed to confirm its efficacy in preventing surgical recurrence.

Erythrocyte deformability and oxidative stress in inflammatory bowel disease

BACKGROUND

Oxidative stress and reduced microvascular flow are important factors in the pathogenesis of inflammatory bowel disease (IBD). The increased oxidative stress reduces the erythrocyte deformability. However, in IBD, there are no studies in the literature which evaluate erythrocyte deformability.

AIMS

In our study, we investigated the effect of oxidative stress and erythrocyte deformability in IBD.

METHODS

Forty-three patients with active IBD, 48 patients with inactive IBD and 45 healthy controls were included. The erytrocyte deformability, malonyldialdehyde levels, glutation peroxidase and sulfhydryl levels were measured in peripheral venous blood samples.

RESULTS

Erytrocyte malonyldialdehyde levels in both active and inactive IBD were significantly increased compared with control groups. Plasma glutation peroxidase levels did not show statistically significant difference between all groups. The decreased plasma sulfhydryl levels in active IBD were statistically significant compared with both the inactive IBD and the control group, but plasma sulfhydryl levels in inactive IBD group did not show statistically significant differences when compared with the control group. Elongation index values in both active and inactive IBD increased significantly compared with the control group. Statistically significant correlations were not found between the elongation index and glutation peroxidase, malonyldialdehyde, sulfhydryl levels in all groups.

CONCLUSIONS

Our study is the first to evaluate the erythrocyte deformability in IBD. In our study, increased erytrocyte malonyldialdehyde levels and decreased plasma sulfhydryl levels manifested the role of oxidative stress in the pathogenesis of the disease. It is thought that the increased erythrocyte malonyldialdehyde values cause the reduction in erythrocyte deformability.

Daikenchuto (TU-100) ameliorates colon microvascular dysfunction via endogenous adrenomedullin in Crohn's disease rat model

BACKGROUND

Daikenchuto (TU-100), a traditional Japanese medicine, has been reported to up-regulate the adrenomedullin (ADM)/calcitonin gene-related peptide (CGRP) system, which is involved in intestinal vasodilatation. The microvascular dysfunction of the intestine in Crohn's disease (CD), due to down-regulation of the ADM/CGRP system, is etiologically related to the recurrence of CD. Therefore, we investigated the vasodilatory effect of TU-100 in a CD rat model.

METHODS

Colitis was induced by the rectal instillation of 2,4,6-trinitrobenzenesulfonic acid (TNBS) in rats. Laser Doppler blood flowmetry was used to measure colonic blood flow. ADM, CGRP, and their receptors in the ischemic colon were measured by reverse transcription polymerase chain reaction (RT-PCR) and enzyme immunoassays. Additionally, we determined whether the intestinal epithelial cell line IEC-6 released ADM in response to TU-100.

RESULTS

TU-100 increased blood flow in ischemic segments of the colon but not in hyperemic segments. Pretreatment with an antibody to ADM abolished the vasodilatory effect of TU-100. CGRP levels and βCGRP mRNA expression were decreased in the ischemic colon, while protein and mRNA levels of ADM were unchanged. Hydroxy α-sanshool, the main constituent of TU-100, was the most active component in improving blood flow. Additionally, both TU-100 and hydroxy α-sanshool enhanced the release of ADM from IEC-6 cells.

CONCLUSIONS

In the ischemic colon, endogenous βCGRP, but not ADM, was decreased. Thus, it was concluded that TU-100 ameliorated microvascular dysfunction by the up-regulation of endogenous ADM in the CD rat model. TU-100 may be a possible therapeutic agent for gastrointestinal ischemia-related diseases including CD.

Aspirin in the aetiology of Crohn's disease and ulcerative colitis: a European prospective cohort study

BACKGROUND

Aspirin has detrimental effects on the gastrointestinal tract mucosa and may play a role in the aetiology of inflammatory bowel disease.

AIM

To investigate if the regular use of aspirin is associated with the development of Crohn's disease (CD) and ulcerative colitis (UC) using, for the first time, a prospective cohort study design.

METHODS

A total of 135,780 men and women in Europe, aged 30-74years, were recruited into the European Prospective Investigation into Cancer and Nutrition study. Participants completed questionnaires at baseline detailing their regular aspirin use and were then followed up to identify those who developed either incident CD or UC. Each case was matched with four controls and odds ratios (OR) were calculated, adjusting for cigarette smoking. Potential interactions between aspirin and smoking were assessed.

RESULTS

A total of 35 participants developed CD and a further 84 were diagnosed with UC. Regular aspirin intake was positively associated with the risk of developing CD (OR=6.14, 95% CI=1.76-21.35). In those who took aspirin and smoked there was no detectable increased risk of CD (OR=0.30, 95% CI=0.03-3.08). No association was found between regular aspirin use and UC (OR=1.29, 95% CI=0.67-2.46).

CONCLUSIONS

A strong positive association between regular aspirin use and CD, but not UC, was observed. The data suggest that regular aspirin use should be measured in epidemiological work on CD. If such findings are consistent in other work then aspirin may affect the development of CD in a middle-aged to elderly population.

A new antimesenteric functional end-to-end handsewn anastomosis: surgical prevention of anastomotic recurrence in Crohn's disease

BACKGROUND

Recurrence of Crohn's disease usually occurs at anastomotic sites.

OBJECTIVE

A new anastomosis technique (Kono-S anastomosis) designed to minimize anastomotic restenosis was compared with conventional anastomoses.

DESIGN AND SETTINGS

The Kono-S anastomosis technique was first used for Crohn's disease in 2003 at the Asahikawa Medical University Hospital. The resection is accomplished by transecting the bowel with a linear cutter so that the mesentery side is located in the center of the stump. Both stumps are sutured to create a supporting column to maintain the diameter and dimension of the anastomosis. Longitudinal enterotomies are made at the antimesenteric sides of the 2 segments of intestine. The side-to-side antimesenteric anastomosis is then performed in transverse fashion. The medical records and follow-up details of all patients undergoing this procedure were reviewed.

PATIENTS

: From 2003 to 2009, 69 patients with Crohn's disease who underwent Kono-S anastomosis (group S) were compared with 73 historical patients with Crohn's disease who underwent conventional anastomosis (group C) from 1993 to 2003.

MAIN OUTCOME MEASURES

A Kaplan-Meier analysis of the follow-up data on surgical recurrence at the anastomosis was performed. The endoscopic recurrence score at the anastomosis was calculated.

RESULTS

The median endoscopic recurrence score in group S was significantly lower than that in group C (2.6 vs 3.4; P = .008). The Kaplan-Meier analysis showed a lesser probability of anastomotic surgical recurrence in the S group at 5 years (0% vs 15%; P = .0013). The absence of postoperative infliximab did not affect the restenosis rate in group S.

LIMITATIONS

This study was limited by its historical retrospective nature.

CONCLUSION

The Kono-S anastomosis appears to be effective in preventing anastomotic surgical recurrence in Crohn's disease.

Postsurgical recurrence of ileal Crohn's disease: an update on risk factors and intervention points to a central role for impaired host-microflora homeostasis

BACKGROUND

A pressing need exists to identify factors that predispose to recurrence after terminal ileal resection for Crohn's disease (CD) and to determine effective prophylactic strategies. This review presents an up-to-date summary of the literature in the field and points to a role for bacterial overproliferation in recurrence.

METHODS

The literature (Medline, Embase, and the Cochrane Library, 1971-2009) on ileal CD and postoperative recurrence was searched, and 528 relevant articles were identified and reviewed.

RESULTS

Smoking is a key independent risk factor for recurrence. NOD2/CARD15 polymorphisms and penetrating phenotype are associated with aggressive disease and higher reoperation rates. Age at diagnosis, disease duration, gender, and family history are inconsistent predictors of recurrence. Prophylactic 5-aminosalicylic acid therapy and nitromidazole antibiotics are beneficial. Combination therapies with immunosuppressants are also effective. Anti-TNFalpha-based regimens show benefit but the evidence base is small. Corticosteroid, interleukin-10, and probiotic therapies are not effective. Wider, stapled anastomotic configurations are associated with reduced recurrence rates. Strictureplasty and laparoscopic approaches have similar long-term recurrence rates to open resection techniques. Length of resection and presence of microscopic disease at resection margins do not influence recurrence. A lack of consensus exists regarding whether the presence of granulomas or plexitis affects outcome.

CONCLUSIONS

Current evidence points to defects in mucosal immunity and intestinal dysbiosis of either innate (NOD2/CARD15) or induced (smoking) origin in postoperative CD recurrence. Prophylactic strategies should aim to limit dysbiosis (antibiotics, side-to-side anastomoses) or prevent downstream chronic inflammatory sequelae (anti-inflammatory, immunosuppressive, and immunomodulatory therapy).

Role of the endothelium in inflammatory bowel diseases

Inflammatory bowel diseases (IBD) are a complex group of diseases involving alterations in mucosal immunity and gastrointestinal physiology during both initiation and progressive phases of the disease. At the core of these alterations are endothelial cells, whose continual adjustments in structure and function coordinate vascular supply, immune cell emigration, and regulation of the tissue environment. Expansion of the endothelium in IBD (angiogenesis), mediated by inflammatory growth factors, cytokines and chemokines, is a hallmark of active gut disease and is closely related to disease severity. The endothelium in newly formed or inflamed vessels differs from that in normal vessels in the production of and response to inflammatory cytokines, growth factors, and adhesion molecules, altering coagulant capacity, barrier function and blood cell recruitment in injury. This review examines the roles of the endothelium in the initiation and propagation of IBD pathology and distinctive features of the intestinal endothelium contributing to these conditions.

On the role of ischemia in the pathogenesis of IBD: a review

Inflammatory bowel disease (IBD) is a chronic intestinal disorder comprising 2 distinct but often overlapping diseases: Crohn's disease and ulcerative colitis. Although much research to identify the etiology of IBD has focused on genetic constitution, infectious causes, and immune dysregulation, its exact cause and pathogenesis remain incompletely understood. Mesenteric blood flow, the intestinal microcirculation, and intestinal ischemia also have been proposed as etiologic, although they remain less-explored themes despite evidence suggesting a contributory role in IBD pathogenesis. The anatomy, architecture, and function of the splanchnic microcirculation will be reviewed here with regard to the development of intestinal microvascular ischemia, a pathologic process that appears to precede the classic changes that characterize IBD.

Mural Crohn disease: correlation of dynamic contrast-enhanced MR imaging findings with angiogenesis and inflammation at histologic examination--pilot study

PURPOSE

To determine mural perfusion dynamics in Crohn disease by using dynamic contrast material-enhanced magnetic resonance (MR) imaging and to correlate these with histopathologic markers of inflammation and angiogenesis.

MATERIALS AND METHODS

Ethical permission was given by the University College London Hospital ethics committee, and informed consent was obtained from all participants. Eleven consecutive patients with Crohn disease (eight female patients, three men; mean age, 39.5 years; range, 16.4-66.6 years) undergoing elective small-bowel resection were recruited between July 2006 and December 2007. Harvey-Bradshaw index, C-reactive protein (CRP) level, and disease chronicity were recorded. Preoperatively, dynamic contrast-enhanced MR imaging was performed through the section of bowel destined for resection, and slope of enhancement, time to maximum enhancement, enhancement ratio, the volume transfer coefficient K(trans), and the extracellular volume fraction v(e) were calculated for the affected segment. Ex vivo surgical specimens were imaged to facilitate imaging-pathologic correlation. Histopathologic sampling of the specimen was performed through the imaged tissue, and microvascular density (MVD) was determined, together with acute and chronic inflammation scores. Correlations between clinical, MR imaging, and histopathologic data were made by using the Kendall rank correlation and linear regression.

RESULTS

Disease chronicity was positively correlated with enhancement ratio (correlation coefficient, 0.82; P = .002). Slope of enhancement demonstrated a significant negative correlation with MVD (correlation coefficient, -0.86; P < .001). There was a negative correlation between CRP level and slope of enhancement (correlation coefficient, -0.77; P = .006). Neither acute nor chronic inflammation score correlated with any other parameter.

CONCLUSION

Certain MR imaging-derived mural hemodynamic parameters correlate with disease chronicity and angiogenesis in Crohn disease, but not with histologic and clinical markers of inflammation. Data support the working hypothesis that microvessel permeability increases with disease chronicity and that tissue MVD is actually inversely related to mural blood flow.

Is there an association between intestinal perfusion and Crohn's disease activity? A feasibility study using contrast-enhanced ultrasound

A recent study used contrast-enhanced ultrasound to assess splanchnic haemodynamics. This study investigates whether an association exists between disease activity and splanchnic transit time in patients with suspected Crohn's disease. The study protocol had the approval of the local ethics committee, and written informed consent was obtained. 18 patients (11 women; mean age, 40 years; age range, 23-69 years) with suspected or confirmed Crohn's disease were recruited prospectively. A bolus injection of an ultrasound contrast agent was given via a peripheral vein and time-intensity curves of the superior mesenteric artery and vein were analysed. Splanchnic transit time was calculated as the time interval between the rise in signal intensity to >10% above baseline value. Baseline parameters measured included the time-averaged maximum velocity and cross-sectional area of the superior mesenteric artery (SMA). Pearson correlations were used to test associations between different numeric measurements; the independent samples t-test was used to test associations between different numeric measurements; and the independent samples t-test was used to compare mean values between patients with active and inactive disease. There was a weak negative association between splanchnic transit time and the Crohn's Disease Activity Index (CDAI) (r = -0.42), which did not reach statistical significance (p = 0.13), although the mean splanchnic transit time was reduced in the active group (4.0 s vs 6.9 s). The SMA flow rate was significantly greater in active disease (37 ml s(-1) vs 22 ml s(-1); Mann-Whitney U, p = 0.02). This study demonstrates the feasibility of using contrast-enhanced ultrasound as an assessment tool for Crohn's disease.

Multiple pathogenic roles of microvasculature in inflammatory bowel disease: a Jack of all trades

The etiology of Crohn's disease and ulcerative colitis, the two major forms of inflammatory bowel disease (IBD), is still largely unknown. However, it is now clear that the abnormalities underlying pathogenesis of intestinal inflammation are not restricted to those mediated by classic immune cells but also involve nonimmune cells. In particular, advances in vascular biology have outlined a central and multifaceted pathogenic role for the microcirculation in the initiation and perpetuation of IBD. The microcirculation and its endothelial lining play a crucial role in mucosal immune homeostasis through tight regulation of the nature and magnitude of leukocyte migration from the intravascular to the interstitial space. Chronically inflamed IBD microvessels display significant alterations in microvascular physiology and function compared with vessels from healthy and uninvolved IBD intestine. The investigation into human IBD has demonstrated how endothelial activation present in chronically inflamed IBD microvessels results in a functional phenotype that also includes leakiness, chemokine and cytokine expression, procoagulant activity, and angiogenesis. This review contemplates the newly uncovered contribution of intestinal microcirculation to pathogenesis and maintenance of chronic intestinal inflammation. In particular, we assess the multiple roles of the microvascular endothelium in innate immunity, leukocyte recruitment, coagulation and perfusion, and immune-driven angiogenesis in IBD.

Multiple pathogenic roles of microvasculature in inflammatory bowel disease: a Jack of all trades

The etiology of Crohn's disease and ulcerative colitis, the two major forms of inflammatory bowel disease (IBD), is still largely unknown. However, it is now clear that the abnormalities underlying pathogenesis of intestinal inflammation are not restricted to those mediated by classic immune cells but also involve nonimmune cells. In particular, advances in vascular biology have outlined a central and multifaceted pathogenic role for the microcirculation in the initiation and perpetuation of IBD. The microcirculation and its endothelial lining play a crucial role in mucosal immune homeostasis through tight regulation of the nature and magnitude of leukocyte migration from the intravascular to the interstitial space. Chronically inflamed IBD microvessels display significant alterations in microvascular physiology and function compared with vessels from healthy and uninvolved IBD intestine. The investigation into human IBD has demonstrated how endothelial activation present in chronically inflamed IBD microvessels results in a functional phenotype that also includes leakiness, chemokine and cytokine expression, procoagulant activity, and angiogenesis. This review contemplates the newly uncovered contribution of intestinal microcirculation to pathogenesis and maintenance of chronic intestinal inflammation. In particular, we assess the multiple roles of the microvascular endothelium in innate immunity, leukocyte recruitment, coagulation and perfusion, and immune-driven angiogenesis in IBD.

Sonographic assessment of splanchnic arteries and the bowel wall

The intestinal wall can be visualized using high resolution transabdominal ultrasound. The normal intestinal wall thickness in the terminal ileum, cecum, and right and left colon is <2mm when examined with graded compression. It is important to appreciate that a contracted intestinal segment can be misinterpreted as a thickened wall. Vascularisation can be mainly displayed in the second hyperechoic layer (submucosal layer) as well as vessels penetrating the muscularis propria. Imaging of the gastrointestinal wall is dependent on the experience of the examiner as well dependent on the equipment used. Acute or chronic inflammation of the intestinal wall is accompanied by increased perfusion of the mesentery, which can be displayed non-quantitatively with colour duplex. In contrast, ischemia is characterised by hypoperfusion of the mesenteric arteries and the bowel wall. The most promising sonographic approach in assessing splanchnic arteries and the bowel wall is combining the analysis of superior and inferior mesenteric inflow by pulsed Doppler scanning (systolic and diastolic velocities, resistance index) with the end-organ vascularity by colour Doppler imaging diminishing the influence of examination technique only displaying bowel wall vascularity. Colour Doppler imaging has been described as helpful in a variety of gastrointestinal disorders, particularly in patients with Crohn's disease, celiac disease, mesenteric artery stenosis and other ischemic gastrointestinal diseases, graft versus host disease and hemorrhagic segmental colitis.

A meta-analysis comparing conventional end-to-end anastomosis vs. other anastomotic configurations after resection in Crohn's disease

PURPOSE

This study compared outcomes between end-to-end anastomosis and other anastomotic configurations after intestinal resection for patients with Crohn's disease by using meta-analytical techniques.

METHODS

Comparative studies published between 1992 and 2005 of end-to-end anastomosis vs. other anastomotic configurations were included. Using a random effects model, end points evaluated were short-term complications and perianastomotic recurrence of Crohn's disease. Heterogeneity was assessed and sensitivity analysis was performed to account for bias in patient selection.

RESULTS

Eight studies (2 prospective, randomized, controlled trials; 1 nonrandomized, prospective; 5 nonrandomized, retrospective studies) reported on 661 patients who underwent 712 anastomoses, of which 383 (53.8 percent) were sutured end-to-end anastomosis and 329 (46.2 percent) were other anastomotic configurations (259 stapled side-to-side, 59 end-to-side or side-to-end, 11 stapled circular end-to-end). Anastomotic leak rate was significantly reduced in the other anastomotic configurations group (odds ratio (OR), 4.37; P = 0.02) and remained significantly lower in studies comparing only side-to-side anastomosis vs. end-to-end anastomosis (OR, 4.37; P = 0.02) and studies including only ileocolonic anastomosis (OR, 3.8; P = 0.05). Overall postoperative complications (OR, 2.64; P < 0.001), complications other than anastomotic leak (OR, 1.89; P = 0.04), and postoperative hospital stay (weighted mean difference, 2.81; P = 0.007) were significantly reduced in the side-to-side anastomosis group when considering studies comparing only side-to-side anastomosis vs. end-to-end anastomosis. There was no significant difference between the groups in perianastomotic recurrence and reoperation needed because of perianastomotic recurrence.

CONCLUSIONS

End-to-end anastomosis after resection for Crohn's disease may be associated with increased anastomotic leak rates. Side-to-side anastomosis may lead to fewer anastomotic leaks and overall postoperative complications, a shorter hospital stay, and a perianastomotic recurrence rate comparable to end-to-end anastomosis. Further randomized, controlled trials should be performed for confirmation.

Inflammation and the mucosal microcirculation in inflammatory bowel disease: the ebb and flow

PURPOSE OF REVIEW

Inflammatory bowel disease pathogenesis involves the interplay of multiple biological factors, among which nonimmune cells, including the endothelium, represent a crucial component of disease pathogenesis.

RECENT FINDINGS

Endothelial cells play a key role in chronic inflammation through multiple and disparate activities. The mucosal microvasculature in inflammatory bowel disease is dysfunctional, overexpresses inflammatory molecules and undergoes intense angiogenesis, failing to exert its physiological antiinflammatory and anticoagulant activities.

SUMMARY

The mucosal microcirculation is abnormal in inflammatory bowel disease and represents a novel component of disease pathogenesis; targeting the various abnormalities of the inflammatory bowel disease microcirculation may lead to new forms of therapeutic intervention.

The intestinal microvasculature as a therapeutic target in inflammatory bowel disease

Chronic inflammation is a complex biologic process which involves immune as well as non-immune cells including the microvasculature and its endothelial lining. Growing evidence suggests that the microvasculature plays an integral role in the pathophysiology of inflammatory bowel disease (IBD; Crohn's disease and ulcerative colitis). The microvasculature contributes to chronic inflammation through altered leukocyte recruitment, impaired perfusion, and angiogenesis leading to tissue remodeling. These diverse areas of IBD microvascular biology represent therapeutic targets that are currently undergoing investigation.

Paradox of simultaneous intestinal ischaemia and hyperaemia in inflammatory bowel disease

This review has focused on evidence regarding intestinal perfusion of inflammatory bowel disease (IBD). Basic investigation has defined an altered microvascular anatomy in the affected IBD bowel, which corresponds with diminished mucosal perfusion in the setting of chronic, long-standing inflammation. Diminished perfusion is linked to impaired wound healing, and may contribute to the continued refractory mucosal damage, which characterizes IBD. Alterations in vascular anatomy and physiology in IBD suggests additional possible mechanisms by which micro-vessels may contribute to the initiation and perpetuation of IBD. This begs the following questions: will angiogenesis within the gut lead to sustained inflammation, does the growing vasculature generate factors that transform the surrounding tissue and does angiogenesis generate vascular anastomosis within the gut, with shunting of blood away from the mucosal surface, impairment of metabolism and potentiation of gut damage? Further studies are required to define the mechanisms that underlie the vascular dysfunction and its role in pathophysiology of IBD.

Serum bFGF and VEGF correlate respectively with bowel wall thickness and intramural blood flow in Crohn's disease

Serum levels of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF)--two factors known to promote tissue repair, fibroblast proliferation, and angiogenesis--were measured in Crohn's disease patients and correlated with bowel wall thickness (BWT), measured by conventional grey scale ultrasonography, and with the ileal intramural vessel flow, measured by contrast-enhanced color Doppler imaging. Serum samples were obtained from 25 patients with active Crohn's disease and 22 healthy volunteers, all sex- and age-matched. Serum bFGF and VEGF levels were measured by ELISA assay. All the patients were examined with conventional transabdominal bowel sonography. Color Doppler of the intramural enteric vessels was then performed after the intravenous injection of Levovist, a galactose-based sonographic contrast agent. In Crohn's disease patients, serum bFGF and VEGF were significantly higher compared with healthy volunteers. A positive correlation between serum bFGF and BWT and between serum VEGF and color Doppler signal intensity was found. The raised serum bFGF levels in Crohn's disease patients with intestinal strictures compared with patients with other phenotypes (fistulizing, inflammatory), together with the correlation observed between serum bFGF and BWT, suggests a possible involvement of bFGF in the process of transmural fibrogenesis in Crohn's disease. The higher levels of VEGF in those patients with increased intramural blood flow suggests that VEGF may be considered a marker of angiogenesis in this condition.

Acquired microvascular dysfunction in inflammatory bowel disease: Loss of nitric oxide-mediated vasodilation

BACKGROUND & AIMS

Inflammatory bowel disease (IBD; i.e., Crohn's disease, ulcerative colitis) is characterized by refractory inflammatory ulceration and damage to the intestine. Mechanisms underlying impaired healing are not defined. Because microvascular dysfunction resulting in diminished vasodilatory capacity and tissue hypoperfusion is associated with impaired wound healing, we hypothesized that microvascular dysfunction may also occur in chronic IBD.

METHODS

Intact submucosal arterioles from control, involved, and uninvolved IBD specimens were assessed using in vitro videomicroscopy to assess endothelium-dependent vasodilation in response to acetylcholine (Ach) and fluorescence microscopy to detect oxyradicals.

RESULTS

Normal microvessels dilated in a dose-dependent and endothelium-dependent manner to Ach (maximum, 82% +/- 2%; n = 34). Inhibition of nitric oxide synthase with N(G)-nitro-L-arginine methyl ester (L-NAME) reduced maximal dilation to 54% +/- 6% (P < 0.05, n = 7), and further reduction was observed after inhibiting cyclooxygenase (indomethacin; 23% +/- 10%, n = 6). Chronically inflamed IBD microvessels showed significantly reduced Ach-induced vasodilation (maximum, 15% +/- 2%; n = 33), with no effect of L-NAME. Indomethacin eliminated the remaining Ach-induced vasodilation, resulting in frank vasoconstriction (-54% +/- 9%, n = 6). Uninvolved IBD gut vessels and non-IBD inflammatory controls responded in a fashion similar to normal vessels. IBD-involved microvessels generated significantly higher levels of reactive oxygen species compared with control and uninvolved IBD vessels (P < 0.01).

CONCLUSIONS

Human intestinal microvessels from chronically inflamed IBD show microvascular endothelial dysfunction, characterized by loss of NO-dependent dilation that may contribute to reduced perfusion, poor wound healing, and maintenance of chronic inflammation.

Intestinal blood flow in murine colitis induced with dextran sulfate sodium

The aim of this study was to assess whether colitis induced by dextran sulfate sodium (DSS; 10% in tap water for 7 days) in BALB/c mice is associated with changes in intestinal blood flow. After anaesthesia, systemic hemodynamic variable and regional blood flows and resistances in various organs were measured in both control and DSS-treated mice. Mean arterial blood pressure was significantly lower in DSS-treated mice than in controls (56 +/- 4 vs 66 +/- 3 mm Hg; P < 0.05), but no differences were found in regional blood flows to or vascular resistances in the lungs, liver, stomach, small intestine (upper, middle, and lower part), cecum, mesentery + pancreas, spleen, kidneys, brain, and skin. However, compared to the control mice, blood flows in the middle (0.88 +/- 0.13 vs 0.55 +/- 0.09 ml/min/g; P < 0.05) and distal (0.69 +/- 0.11 vs 0.29 +/- 0.05 ml/min/g; P < 0.05) colon were significantly higher, and vascular resistances in the proximal (0.87 +/- 0.21 vs 1.36 +/- 0.21 mm Hg min/ml/100 g; P < 0.05), middle (0.60 +/- 0.10 vs 1.46 +/- 0.35 mm Hg min/ml 100 g; P < 0.05) as well as distal (0.90 +/- 0.25 vs 2.67 +/- 0.49 mm Hg min/ml/100 g; P < 0.05) colon were significantly lower in mice with experimental colitis. Interestingly, there was a gradient in the intestinal blood flow in control mice from the upper small intestine (2.79 +/- 0.72 ml/min/g) down to the distal colon (0.29 +/- 0.05 ml/min/g); such a gradient was also present in the colitis mice. It is concluded that DSS-induced colitis in mice is associated with microcirculatory disturbances in the colon, mainly in its middle and distal parts.

Doppler enhancement after intravenous levovist injection in Crohn's disease

Although transabdominal bowel sonography (TABS) has been proposed as a reliable tool to assess increased bowel wall thickness (BWT), the most common sonographic pattern in patients with Crohn's disease (CD), its accuracy is limited in the diagnosis of CD. We therefore tried to assess whether color Doppler enhancement with Levovist, a galactose-based intravenous sonographic contrast agent able to enhance the arterial Doppler signal, increases TABS accuracy. Thirty-one patients with ileal CD, diagnosed by endoscopy and enteroclysis, and 20 healthy volunteers were examined with conventional TABS. Color Doppler of the intramural enteric vessels was then performed before and after intravenous injection of Levovist. Twenty-two CD patients had a BWT >4 mm, and 16 of them presented with active disease. Two of the remaining nine CD patients, all with BWT <4 mm, presented with active disease. By means of color Doppler we identified six patients with inactive disease, normal BWT, and normal basal Doppler signal intensity, who showed an enhanced Doppler signal in intramural vessels after contrast agent bolus. Four of these patients, identified only by color Doppler after Levovist injection, relapsed within 6 months. In our experience, sensitivity and specificity of TABS, integrated with additional stimulated acoustic emission mode, were 96.7% and 100%, respectively. The use of Levovist in color Doppler increases the accuracy of TABS in CD diagnosis and follow-up.

Jejunal and gastric mucosal perfusion versus splanchnic blood flow and metabolism: an observational study on postcardiac surgical patients

OBJECTIVES

To evaluate the association between changes in total splanchnic and mucosal perfusion, assessed either by gastric tonometry or jejunal laser Doppler flowmetry in postcardiac surgical patients.

DESIGN

A prospective, observational study.

SETTINGS

A general intensive care unit in a tertiary care center.

PATIENTS

Twelve, postoperative cardiac surgery patients were studied.

INTERVENTIONS

Patients were treated according to clinical routine. Total splanchnic blood flow (indocyanine green extraction), jejunal mucosal perfusion (laser Doppler flowmetry), gastric mucosal-arterial PCO2 gradients, and splanchnic lactate uptake were studied during four 30-min measurements periods, each separated by a period of 1 hr.

MEASUREMENTS AND MAIN RESULTS

There was no consistent association between either total splanchnic and local mucosal perfusion or between gastric and jejunal perfusion as assessed by two different techniques. The PCO2 gradient increased from 0.73+/-0.21 kPa to 1.15+/-0.30 kPa (p < .05), and splanchnic oxygen extraction increased from 40%+/-9% to 49%+/-14% (p < .01).

CONCLUSIONS

In this observational study on postcardiac surgical patients, local mucosal perfusion did not reflect total splanchnic blood flow and vice versa. Either changes in gastric and jejunal mucosal perfusion were different or increasing tissue metabolism was responsible for the observed lack of association between tonometry, laser Doppler flowmetry, and total splanchnic blood flow. Increasing mucosal arterial PCO2 gradient and splanchnic oxygen extraction may reflect a mismatch between splanchnic perfusion and metabolic demands.

Differential effects of dopamine, dopexamine, and dobutamine on jejunal mucosal perfusion early after cardiac surgery

OBJECTIVE

To evaluate the potential differential effects of dopamine, dopexamine, and dobutamine on jejunal mucosal perfusion, assessed by endoluminal laser Doppler flowmetry in uncomplicated postcardiac surgical patients.

DESIGN

A prospective, blinded, randomized, crossover study.

SETTING

A cardiothoracic intensive care unit in a tertiary care center.

PATIENTS

A total of ten postoperative cardiac surgical patients were studied.

INTERVENTIONS

Each patient received sequentially, randomly, and in a blinded fashion 2.7+/-0.2 microg x kg(-1) x min(-1) dopamine, 0.7+/-0.1 microg x kg(-1) x min(-1) dopexamine, and 2.7+/-0.1 microg x kg(-1) x min(-1) dobutamine. Each inotropic agent was titrated to increase cardiac output by 25% from baseline. Data on jejunal mucosal perfusion, splanchnic lactate, and oxygen extraction were obtained during a 5-min control period and a 5-min drug infusion period after the target cardiac output was reached. The procedure was sequentially repeated for each agent, and there was a 20- to 30-min washout period between each agent.

MEASUREMENTS AND MAIN RESULTS

Dopamine, dopexamine, and dobutamine increased jejunal mucosal perfusion by 27% (p < .01), 20% (p < .001), and 7% (p < .001), respectively. The increase in jejunal mucosal perfusion by dopamine and dopexamine were significantly more pronounced compared with dobutamine (p < .05 and p < .01, respectively), whereas there was no difference between dopamine and dopexamine. Splanchnic oxygen extraction decreased to the same extent with all three drugs. Splanchnic lactate extraction did not change for any of the drugs. The effects on central hemodynamics were similar for the three inotropic agents.

CONCLUSIONS

Endoluminal laser Doppler flowmetry is a new tool for the detection of perfusion changes at the local intestinal mucosal level. Dopamine, dopexamine, and dobutamine have differential effects on jejunal mucosal perfusion probably because of their different receptor stimulating properties. These findings may be of clinical importance when the therapeutic goal is to improve gut mucosal perfusion.

Interaction between blood flow and motility in normal and inflamed ileum

The alterations in local and superior mesenteric blood flow during ileal inflammation and their correlations with motility in the normal and the inflamed ileum were investigated in the conscious state. Ileal inflammation decreased the local mesenteric blood flow but had no significant effect on the superior mesenteric blood flow. A significant reduction or an increase in local mesenteric blood flow in the normal or the inflamed ileum had no effect on local contractile activity. The vascular reactivity to vaso-dilators and vaso-constrictors was significantly reduced during inflammation. Local mesenteric blood flow increased significantly in the descending segment ahead of a caudal propagating giant migrating contraction. The local mesenteric blood flow oscillated during a migrating motor complex (MMC) cycle. We conclude that a several-fold increase or decrease in local mesenteric blood flow lasting for several minutes does not affect contractility. Ileal inflammation decreases local mesenteric blood flow but does not affect the total blood flow to the small intestine.

Remodeling of vascular wall in Crohn's disease

To clarify the changes in vascular resistance in Crohn's disease, we studied changes in the thickness of arterial media histometrically. The resected specimens of mesenterium and intestine from 18 patients with Crohn's disease were used. Each intestinal lesion was classified into three grades: no inflammation, exudative change, and fibrosing change. In the ileum, significant atrophy in the media of the submucosal peripheral arteries was noted during exudative and fibrosing changes, while in the submucosal larger vessels or in the mesenterium, the thickness of the arterial media did not change. In the colon, atrophy in the media of the submucosal arteries was noted in all stages except in the larger vessel during exudative change, while no significant changes were noted in the mesenterium. In conclusion, it is suggested that circulatory disturbance occurs even in the early stage in Crohn's disease, and there seems to be increased vascular resistance in the area between the deep submucosal and the distal mesenteric arteries.

Mesenteric blood flow is related to disease activity and risk of relapse in Crohn's disease: a prospective follow-up study

OBJECTIVE

The diagnostic significance of increased splanchnic blood flow in Crohn's disease is unclear. This prospective study was therefore undertaken to define the role of Doppler sonography in the assessment of disease activity and in the prediction of early relapse.

METHODS

Splanchnic flowmetry was performed in 59 patients with Crohn's disease and 20 healthy volunteers during fasting and 30 min after ingestion of a standardized meal. Twenty-one patients measured during the active state and in clinical remission were followed-up for 6 months. Hemodynamic parameters of the superior and inferior mesenteric arteries and the portal vein were related to clinical (Crohn's disease activity index [CDAI]), laboratory (C-reactive protein), and endoscopic (Crohn's Disease Endoscopic Index of Severity) parameters of disease activity.

RESULTS

The postprandial mean velocity of the superior mesenteric artery correlated closest with clinical activity (CDAI, p < 0.005) and C-reactive protein (p < 0.01), but was unrelated to endoscopic activity. All patients in remission after 6 months (9/9) showed an increase in postprandial pulsatility index of the superior mesenteric artery, compared with an initial measurement during active disease (+28%). In contrast, the majority of patients with later relapse or surgery (11/12) had decreased pulsatility index during initial remission (-20%). The positive predictive value of this index for maintenance of remission was 0.82.

CONCLUSIONS

Postprandial flow measurements in the superior mesenteric artery are closely related to clinical but not endoscopic disease activity in patients with Crohn's disease. The repeated measurement of the postprandial pulsatility index allows estimation of the risk of recurrence.

Temporal patterns of colonic blood flow and tissue damage in an animal model of colitis

This study tested the hypothesis that altered colonic blood flow may contribute to tissue damage during the development of colitis in the rabbit. This was achieved by using radioactive microspheres to measure colonic blood flow at various times after colitis induction with trinitrobenzene sulfonic acid. Significant colonic damage occurred 6 hours post colitis induction and persisted throughout the 5 day study. Blood flow to the muscularis propria and mucosa/muscularis mucosae compartments increased significantly from 5 minutes until one hour post induction. At 6 and 12 hours post induction colonic blood flow returned to control levels before increasing again from 24 to 96 hours. This second increase in flow was, however, predominantly in the mucosa/muscularis mucosae compartment. Blood flow in the stomach and non-gastrointestinal tissues did not change significantly at any time. These data demonstrate that increased colonic blood flow may be disrupted in the early stages of colitis and that this coincides with the onset of significant damage. It is concluded that maintenance of elevated colonic blood flow throughout the development of colitis may help to ameliorate subsequent tissue injury.

Side-to-side stapled anastomosis may delay recurrence in Crohn's disease

PURPOSE

Perianastomotic recurrence after resection in Crohn's disease may be related to ischemia and subacute obstruction at the anastomosis. A technique designed to minimize these factors currently is being evaluated.

METHODS

From 1984 to 1997 69 patients underwent resection and primary anastomosis for symptomatic Crohn's disease (17 jejunal or ileal, 72 ileocolic, and 7 colocolic resections). Of these, 42 patients underwent functional end-to-end anastomoses with the use of linear cutting staplers (Proximate 75 mm or GIA 228 80 mm) and 27 patients underwent end-to-end sutured anastomoses.

RESULTS

In the stapled anastomosis group one (2 percent) patient required reoperation for recurrent symptoms at 46 months. Complications occurred in four (8 percent) patients (one enterocutaneous fistula, one wound infection, one abscess, and one ileus). There were no anastomotic leaks. The median postoperative stay was seven (range, 5-26) days. In the sutured anastomosis group 14 (43 percent) patients required 15 further resections for symptomatic recurrence at a median of 46 (range, 4-91) months. Complications occurred in six (17 percent) patients (two anastomotic leaks, two fistulas, one stricture, and one pulmonary embolus). The median postoperative stay was 10 (range, 6-28) days.

CONCLUSIONS

Functional end-to-end stapled anastomoses after resection for Crohn's disease may be associated with fewer complications than sutured anastomoses and may delay reoperation for symptomatic recurrence. Further evaluation of the technique is indicated.