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Background: Managing patients with inflammatory bowel disease requires multidisciplinary coordination. Technological advances have enhanced access to care for patients and improved physician interactions. The primary aim of our project was to convene diverse institutions and specialties through a multisite virtual conferencing platform to discuss complex patient management., Methods: The case conference is designed to include multiple institutions to exchange ideas, review evidence-based data, and provide input on the management of patients with Crohn's disease and ulcerative colitis. Technology is supplied and coordinated by an information technology specialist and Chorus Call, Inc., an international teleconferencing service provider. The Inflammatory Bowel Disease Live Interinstitutional Interdisciplinary Videoconference Education (IBD LIVE) initiative is accredited by the University of Pittsburgh Medical Center (UPMC) Center for Continuing Education in the Health Sciences for 1 AMA PRA Category 1 Credit per weekly session., Results: IBD LIVE began in 2009 comprising only adult gastroenterology and pediatric gastroenterology from UPMC Presbyterian and Children's Hospitals. Participation steadily increased from 5 sites in 2010 to 11 sites in 2014. Maximum attendance for a single conference was 73 participants with a median of 48. The Continuing Medical Education scores (1 = worst to 5 = best) have a high median overall score (4.6, range 3.2-5.0) with positive responses with regard to the degree to which the conference changed practice., Conclusions: IBD LIVE has been successful and continues to grow. Implementation of the Crohn's and Colitis Foundation of America Virtual Preceptor Program using the IBD LIVE platform will provide expanded national physician access to this professional education activity.

Adenomucinosis is a rare condition characterized by accumulation of large volumes of mucin, typically related to mucinous neoplasms of the appendix within the peritoneal space. Extraperitoneal adenomucinosis is an uncommon variant where mucin accumulates outside the peritoneal space and usually arises following surgery for mucinous appendiceal neoplasms. This is a case of subperitoneal adenomucinosis resulting from retention of a small fragment of rectal mucosa following proctocolectomy for ulcerative colitis 16 years prior. The patient presented with a slow-growing boggy perineal mass. Contrast-enhanced magnetic resonance imaging (MRI) showed the mass to be localized to the pelvis, without solid enhancing components, and correctly facilitated local surgical excision without the risk of peritoneal dissemination and accurately predicted benignity., (Copyright © 2011 Wiley-Liss, Inc.)

Background: The financial impact of laparoscopic colectomy remains poorly defined. We report the short-term costs of laparoscopic colectomy (LC) as compared with open colectomy (OC) in a high-volume tertiary care hospital, and are the first to incorporate the costs of late, colectomy-related complications in an analysis of long-term costs., Methods: A retrospective analysis of patients undergoing elective laparoscopic (n = 76) or open (n = 162) colon resection between January 2004 and December 2006 was performed. Primary endpoints were total hospital cost of the index admission and total hospital cost for any subsequent admission for treatment of a colectomy-related complication., Results: Two-hundred thirty-eight patients met inclusion criteria. Mean total hospital cost was significantly greater for patients undergoing OC (US $17,686 per patient versus US $14,518, P = 0.0003). Mean total operative costs were equivalent (US $7,451 OC versus US $7,794 LC, P = 0.274). Average length of stay was shorter for LC (5.2 versus 6.9 days, P < 0.0001). Late complication rates were 5.6% (OC) and 2.6% (LC). Integrating the cost of late complications further increased the disparity between the total cost of OC (US $18,296 per patient, 3.4% increase) as compared with LC (US $14,789, 1.9% increase)., Conclusion: We demonstrate both short- and long-term financial benefits of LC in a high-volume tertiary care hospital.

Background: Our primary aim was to determine if the rate of small bowel resection (SBR) has declined over time among Crohn's disease (CD) patients seen at a single academic institution. A secondary aim was to establish whether the indication for surgery has changed., Methods: Patients with a primary or secondary ICD-9 code for CD (555.0-555.9) who underwent SBR at the University of Pittsburgh were included. Patients were divided into 4 separate time periods based on when they had surgery: 1995-1998 (Period 1), 1999-2001 (Period 2), 2002-2004 (Period 3), and 2005-2007 (Period 4). Medical records were reviewed for the 6 months preceding surgery. Use of 5-ASAs, immunomodulators (IMs), tumor necrosis factor (TNF) antagonists, and corticosteroids were noted. Disease behavior was defined as nonstricturing, nonpenetrating (B1), stricturing (B2), and penetrating (B3). Proportions of patients undergoing SBR were calculated according to calendar cohort and these rates were examined for time trends., Results: In all, 227 unique patients were analyzed for a total of 236 surgeries. The rates of 5-ASA, IM, and corticosteroid use were similar across the 4 time periods. By contrast, TNF antagonist usage progressively increased over time (0%, 18%, 34%, 35%; P = 0.0002). The annual rate of SBR per period did not change (1.6%, 1.9%, 1.6%, 1.9%; P = 0.93). Similarly, the disease behavior did not change over time., Conclusions: While the frequency of TNF antagonist use in CD at the University of Pittsburgh has increased over time, the rate of SBR and indication for surgery has remained unchanged. These findings may be explained by long-standing, complicated disease refractory to medical therapy.

Filiform polyposis is an uncommon entity that is most often encountered in the colon of patients with a history of inflammatory bowel disease (IBD). Filiform polyposis is characterized by a large number of "wormlike" polyps lined by histologically normal colonic mucosa. These polyps can mimic adenomatous polyps. Only rare cases without a history or evidence of IBD have been reported. Neuromuscular and vascular hamartoma of the small bowel is a rare, focal disorder characterized by disorganized smooth muscle fascicles throughout the submucosa accompanied by fibrosis, nerve fibers, ganglion cells, and vessels. To our knowledge, there is only one report of this lesion in the large bowel (cecum), where it presented as a mass. Here we report the case of a 50-year-old man with no known history or symptoms of IBD presenting with filiform polyposis involving the entire colon, clinically mimicking familial adenomatous polyposis, and showing histologic features similar to neuromuscular and vascular hamartoma of the small bowel.

Gastrointestinal stromal tumors are rare tumors of the gastrointestinal tract. Gastrointestinal stromal tumors involving the rectum are uncommon. We describe a case of a 43-year-old female with a gastrointestinal stromal tumor of the rectum who declined abdominoperineal resection. Neoadjuvant treatment with imatinib decreased her tumor size, permitting sphincter-sparing transanal excision. She had no evidence of disease for 24 months postoperatively until she recurred with lung metastases. Microdissection genotyping of the recurrent lesion revealed a deletion in exon 11. Further mutational analysis showed that her metastatic lesion was concordant with her primary rectal lesion, suggesting that systemic micrometastasis was previously present at initial diagnosis. Deletion in exon 11 predicts for response with imatinib treatment and is associated with a longer event-free and overall survival. Current studies are underway that may help us optimize the treatment for patients with gastrointestinal stromal tumors.

Objective: To investigate the initiation of a complex inflammatory response within the human intestinal muscularis intraoperatively so as to determine the clinical applicability of the inflammatory hypothesis of postoperative ileus., Summary Background Data: Mild intestinal manipulation in rodents initiates the activation of transcription factors, upregulates proinflammatory cytokines, and increases the release of kinetically active mediators (nitric oxide and prostaglandins), all of which results in the recruitment of leukocytes and a suppression in motility (i.e., postoperative ileus)., Methods: Human small bowel specimens were harvested during abdominal procedures at various times after laparotomy. Histochemical and immunohistochemical techniques were applied to intestinal muscularis whole-mounts. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed for interleukin (IL)-6, IL-1beta, tumor necrosis factor (TNF)-alpha, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Signal transducers and activators of transcription (STAT) protein phosphorylation was determined by electromobility shift assay. Organ bath experiments were performed on jejunal circular smooth muscle strips. GW274150C and DFU were used in vitro as iNOS and COX-2 inhibitors., Results: Normal human muscularis externa contained numerous macrophages that expressed increased lymphocyte function associated antigen-1 (LFA-1) immunoreactivity as a function of intraoperative time. RT-PCR demonstrated a time-dependent induction of IL-6, IL-1beta, TNF-alpha, iNOS, and COX-2 mRNAs within muscularis extracts after incision. Mediators were localized to macrophages with STAT protein activation in protein extracts demonstrating local IL-6 functional activity. DFU alone or in combination with GW274150C increased circular muscle contractility. Specimens harvested after reoperation developed leukocytic infiltrates and displayed diminished in vitro muscle contractility., Conclusions: These human data demonstrate that surgical trauma is followed by resident muscularis macrophage activation and the upregulation, release, and functional activity of proinflammatory cytokines and kinetically active mediators.

Background & Aims: Ischemia-reperfusion injury or intestinal manipulation evokes an inflammatory response within the intestinal muscularis that is associated with intestinal dysmotility. We hypothesize that human small intestinal transplantation induces an analogous response., Methods: Human intestinal graft specimens were obtained during transplantation and compared with specimens removed early during elective bowel resections. Inflammatory gene expression was quantified by real-time reverse-transcription polymerase chain reaction. Histochemistry and immunohistochemistry were used to characterize leukocyte infiltration and macrophage activation. In vitro circular muscle contractility and intracellular electric neuromuscular transmission in response to electric field stimulation (EFS) were measured., Results: Messenger RNA (mRNA) values were significantly elevated before reperfusion and further increased during reperfusion (4 hour reperfusion: interleukin [IL]-6, 311-fold; monocyte chemoattractant protein [MCP-1, 122-fold; IL-8, 338-fold; epithelial neutrophil-activating peptide-78 [ENA-78], 56-fold; intercellular adhesion molecule-1 [ICAM-1], 9-fold; and cyclooxygenase-2 [COX2], 37-fold) over elective specimens. Neutrophils and monocytes extravasated in increased numbers in whole mounts before and after reperfusion over the elective specimens. Activated resident macrophages were identified as a major source of inflammatory mediators. Muscle contractions and neuromuscular transmission were markedly attenuated in the grafts., Conclusions: The data suggest that manipulation during organ harvesting initiates a functionally relevant molecular and cellular inflammatory response within the graft muscularis that is potentiated during the reperfusion period. Significant mechanical and neuromuscular functional alterations occurred during the transplant process.

The surgical management of patients with CD can be complex and fraught with complications. Thorough preoperative evaluation by a multidisciplinary management team should delineate the indications for surgery and allow formulation of an operative strategy. Although surgery is not a cure for CD, approximately three quarters of patients require an operation. Until better postoperative maintenance strategies are developed, many CD patients eventually require a reoperation.

Background and Aims: Dysfunction of the immune system with inappropriate responses of lymphocytes to various antigens has been implicated in the development of Crohn's disease. Therefore, the functional and phenotypic characteristics of intestinal intraepithelial lymphocytes (IEL) in comparison to peripheral blood lymphocytes (PBL) were analyzed in patients with and without Crohn's disease., Patients and Methods: Six patients with Crohn's disease and six control patients were studied. Isolated IEL and PBL were tested for cytolytic activity against the human adenocarcinoma cells DLD-1 and the human leukemia cells K562 in a 51Cr-release assay. Two-color flow cytometry was performed for phenotype analysis of isolated lymphocytes., Results: IEL from patients with Crohn's disease showed significantly increased cytolytic activity against epithelial-derived target cells when compared with IEL from control patients. In contrast, no functional changes were detectable among PBL from patients with Crohn's disease. IEL from patients with Crohn's disease contained a significantly higher percentage of CD8+ lymphocytes when compared with IEL from control patients, whereas no phenotypic changes were observed among PBL., Conclusions: In Crohn's disease, the functional and phenotypic changes of T cells are limited to lymphocytes of the intestinal mucosa. Furthermore, it is conceivable that the increased cytolytic activity of IEL contributes to the tissue damage in this disease.

Background & Aims: We have shown that intestinal manipulation leads to a significant inhibition of circular muscle contraction. We hypothesized that the inflammatory mediator inducible nitric oxide (NO) plays a role in surgically induced ileus., Methods: Rats and inducible NO synthase (iNOS) knockout and wild-type mice underwent a simple intestinal manipulation. Reverse-transcription polymerase chain reaction and immunohistochemistry were used to detect and localize iNOS expression. Nitrite and NO production were measured in muscularis cultures. Spontaneous and bethanechol-stimulated jejunal circular muscle contractions were measured in an organ bath., Results: Intestinal manipulation resulted in significant iNOS messenger RNA induction in mucosa and muscularis. Immunohistochemistry localized iNOS in phagocytes within the muscularis. Nitrite and NO production increased 59.8-fold 24 hours after manipulation. L-n(6)-(1-iminoethyl) lysine (L-NIL) inhibited this response. In control rats, selective iNOS inhibition did not increase spontaneous muscle activity, but after manipulation L-NIL significantly improved spontaneous activity. iNOS knockout mice showed a significant 81% decrease in neutrophil infiltration into the muscularis after intestinal manipulation compared with wild-types. Contractile activity was normal in knockout mice after intestinal manipulation., Conclusions: These results show that leukocyte-derived inducible NO inhibits gastrointestinal motility after manipulation and plays an essential role in the initiation of intestinal inflammation.

Background: Surgical manipulation of the intestine results in the massive movement of leukocytes into the intestinal muscularis at 24 hours. This is associated with muscle inhibition. The aim of this study was to temporally associate leukocyte extravasation with ileus after surgical manipulation., Methods: Rats underwent a simple manipulation of the small bowel and were killed at various times (0, 0.25, 0.5, 1, 3, 6, 12, and 24 hours) postoperatively. Jejunal circular-muscle contractile activity was assessed in a standard organ bath. Both extravasating and resident leukocytes were immunohistochemically stained in muscularis whole mounts., Results: Contractile activity was significantly reduced immediately after surgery, but rapidly returned to control levels at 3 hours. After recovery, muscle function decreased at 12 and 24 hours (41% and 81%, respectively). The resident muscularis macrophage network demonstrated cellular activation 1 hour postoperatively. The number of leukocytes increased over time (neutrophils, 67.5-fold; monocytes, 98.2-fold; and mast cells, 47-fold at 24 hours)., Conclusions: The functional results demonstrate a biphasic response in the suppression of muscle activity after surgical manipulation. Regression analysis (r2 = 0.998) of the temporal development of leukocyte infiltration and the protracted phase of muscle inhibition provides evidence for a correlation between cellular inflammation and postoperative dysmotility.

Background & Aims: Postoperative ileus is a poorly understood and common problem. We previously demonstrated an association between a suppression in jejunal circular muscle activity and a massive extravasation of leukocytes into the muscularis after surgical manipulation of the small bowel. This study was pursued to establish a direct causal link between these events., Methods: Reverse-transcription polymerase chain reaction and immunohistochemistry were used to detect and localize expression of adhesion molecules: P-selectin, intercellular adhesion molecule 1 (ICAM-1), and lymphocyte function-associated antigen 1 (LFA-1). Leukocyte infiltration and in vitro jejunal circular muscle function were quantified in controls and manipulated animals with and without antibody treatment (1A29, WT.1, and WT.3)., Results: Surgical manipulation caused a significant up-regulation within the muscularis of ICAM-1 and P-selectin messenger RNA. ICAM-1 and P-selectin protein expression was increased within the muscularis microvasculature, and ICAM-1 and LFA-1 were expressed on infiltrating cells. Administration of adhesion molecule antibodies prevented the recruitment of monocytes and neutrophils into the muscularis and also averted jejunal circular muscle dysfunction., Conclusions: The data demonstrate that adhesion molecule antibodies prevent surgically induced suppression of intestinal muscle contractions and therefore suggests that late postoperative ileus is mediated through a leukocytic inflammatory response within the intestinal muscularis externa.

Background: Currently, therapeutic treatments for irritable bowel syndrome fail to produce significant clinical results. We hypothesized that alosetron, a selective 5-HT3 antagonist, may provide symptomatic relief in irritable bowel syndrome patients through a decrease in the amplitude of gastrointestinal contractions., Aim: To determine the in vitro effect of alosetron on neuromuscular transmission in the canine and human jejunal and colonic muscularis externa., Results: Alosetron diminished electrical field-stimulated (EFS) contractions recorded from muscles of the canine and human small and large intestines. Mechanistically, the diminished EFS response could be explained by the ability of alosetron to decrease the fractional release of 14C-choline radiolabelled acetylcholine evoked by EFS from human jejunal muscle. The inhibition of EFS contractions was not limited to atropine-sensitive events, as non-cholinergic excitatory EFS evoked contractions were also inhibited. Additionally, alosetron at high concentrations (> 30 microM) directly altered bethanechol stimulated contractions., Conclusion: Caution must be used in the interpretation of these data because significant alterations in EFS-induced contractions were only observed with large pharmacological concentrations of alosetron, and the response was not selective for cholinergically-mediated excitatory neuromuscular transmission.

Background: Recent reports suggest that laparoscopic paraesophageal hernia repair (LPHR) is feasible, but no direct comparisons with the standard open paraesophageal hernia repair (OPHR) have been reported. The purpose of this study was to compare the short-term outcome of LPHR versus OPHR at a single institution., Methods: The operative and postoperative courses of 95 consecutive patients undergoing open or laparoscopic repair of a paraesophageal hernia (PEH) were retrospectively reviewed, and outcomes of LPHR versus OPHR were compared., Results: PEH was associated with advanced age and significant comorbidity. Although the operative time was increased for LPHR, there was a significant reduction in blood loss, intensive care unit stay, ileus, hospital stay, and overall morbidity associated with LPHR compared with OPHR., Conclusions: PEH is associated with significant comorbidity that increases the operative risk. Short-term outcomes for LPHR are superior to OPHR, suggesting that the laparoscopic approach is the preferred approach to paraesophageal hernia repair.

Objective: To investigate the pathophysiologic mechanisms that lead to ileus after abdominal surgery., Summary Background Data: The common supposition is that more invasive operations are associated with a more extensive ileus. The cellular mechanisms of postsurgical ileus remain elusive, and few studies have addressed the mechanisms., Methods: Rats were subjected to incremental degrees of surgical manipulation: laparotomy, eventration, "running," and compression of the bowel. On postsurgical days 1 and 7, muscularis infiltrates were characterized immunohistochemically. Circular muscle activity was assessed using mechanical and intracellular recording techniques in vitro., Results: Surgical manipulation caused an increase in resident phagocytes that stained for the activation marker lymphocyte function-associated antigen (LFA-1). Incremental degrees of manipulation also caused a progressive increase in neutrophil infiltration and a decrease in bethanechol-stimulated contractions. Compression also caused an increase in other leukocytes: macrophages, monocytes, dendritic cells, T cells, natural killer cells, and mast cells., Conclusion: The data support the hypothesis that the degree of gut paralysis to cholinergic stimulation is directly proportional to the degree of trauma, the activation of resident gut muscularis phagocytes, and the extent of cellular infiltration. Therefore, postsurgical ileus may be a result of an inflammatory response to minimal trauma in which the resident macrophages, activated by physical forces, set an inflammatory response into motion, leading to muscle dysfunction.

The basal presence of immunologically potent cells within the intestinal muscularis externa and their functional significance is unclear. Our aim was to investigate the basal distribution of various leukocyte populations within the rat jejunal muscularis. In addition, we sought to immunohistochemically phenotype the muscularis macrophage in jejunal whole-mounts, isolate these cells in primary culture, and investigate their ontogenesis. Macrophages form a regularly distributed network that expresses major histocompatibility complex class II, CD14 receptors, and a low level of CD11/CD18. The macrophages are activated by dissection and are present in fetal animals. Enriched macrophage cultures show a normal resident phenotype and remain present for weeks in dissociated muscularis cultures. The results also demonstrate the presence of neutrophils, monocytes, mast cells, and lymphocytes within the muscularis and suggest that the dense network of muscularis macrophages may be a potent resident trigger for inflammation in response to tissue injury or bacterial translocation.

Background: Intestinal grafts are placed either heterotopically (out of continuity) or orthotopically (in continuity); the latter is believed to be advantageous, as intraluminal nutrients and intestinal secretions might modulate the intestinal immune status and possibly delay rejection., Methods: This study was designed to delineate the effects of heterotopic versus orthotopic allograft position on the morphology and function of intestinal smooth muscle in our rat model of chronic rejection. Syngeneic orthotopic grafts were evaluated to control for changes due to the transplantation process., Results: Histochemistry of the graft's muscularis externa showed a significant thickening due to hyperplasia and hypertrophy, which was most pronounced in heterotopic grafts (control = 92+/-2.4 microm, syngeneic grafts = 140+/-6.7 microm, orthotopic allografts = 278+/-26.6 microm, heterotopic allografts = 456+/-50 microm). In terms of function, muscle strips from allografts only generated 23% of the total bethanechol-induced contractile force in vitro compared to unoperated controls and syngeneic grafts. The mean resting membrane potential of control and isograft muscle cells was -69 +/- 0.9 mV with a slow-wave amplitude of 20+/-0.5 mV. Chronic rejection hyperpolarized the resting membrane potential of orthotopic allografts (-66 +/- 0.5 mV) and even more so of heterotopic allografts (-58 +/- 3.4 mV). Slow-wave amplitudes were decreased in orthotopic (14+/-0.9 mV) and nearly abolished in heterotopic allografts (2+/-1.2 mV)., Conclusions: Our data indicate that allografts in heterotopic position are most susceptible to the insult of chronic rejection exemplified by increased proliferative and hypertrophic transformation of intestinal smooth muscle and a marked decrease in mechanical and electrical activity.

Infiltration of a transplanted organ by host lymphoid cells is the hallmark of acute rejection. However, after intestinal transplantation, physiological lymphocyte migration may lead to host cell infiltration of the graft even in the absence of rejection. It is unclear whether this lymphocyte migration also involves the intraepithelial compartment of the graft or whether infiltration there is indicative of acute rejection. We demonstrate here that host cell infiltration of the intestinal mucosa occurs both during acute rejection of a small bowel allograft and, to a lesser extent, when rejection is prevented by immunosuppression with FK506. The infiltrating host cells consisted of CD3+ T cells with a predominant CD4-CD8+ phenotype resembling intraepithelial lymphocytes (IELs). Functional studies showed that the nonspecific cytolytic activity of IELs was not affected by acute rejection or by immunosuppression with FK506. These findings indicate that host cell infiltration of the intestinal mucosa does not connote an ongoing acute rejection. Furthermore, the decreased mucosal barrier function during acute rejection of intestinal allgrafts is probably not due to impaired cytolytic activity of IELs.

Chronic rejection is the major cause of late intestinal allograft dysfunction. We have previously shown that chronic rejection alters the muscularis externa of the graft. This study determined structural and functional changes to the enteric nerves during chronic rejection. Chronic rejection was achieved in orthotopic intestinal transplants (ACI to Lewis) by limited immunosuppression. Syngeneic transplants (ACI to ACI) and unoperated ACI rats served as controls. Animals were clinically healthy and showed no significant alterations in the mucosal architecture on postoperative day 90. Staining for NADPH diaphorase activity (nitric oxide synthase-containing neurons) and with neurofilament antibody RT-97 revealed that chronic rejection decreased the number of jejunal myenteric ganglia by approximately 50%. Inhibitory junction potentials (IJPs) to circular muscle cells were determined by electrical field stimulation (EFS). In controls and syngeneic grafts, EFS caused a stimulus-dependent increase in IJP amplitude, with a maximal amplitude of 9 +/- 0.4 and 10 +/- 0.8 mV, respectively. Chronic rejection in allografts markedly increased the threshold for IJP initiation and decreased the maximal IJP amplitude (5 +/- 0.8 mV). Our data indicate that chronic rejection severely damages the muscularis and the enteric nervous system before mucosal changes become evident.

Mucosal injury is an immediate event following revascularization of small intestinal grafts in the context of transplantation (SBTx). The generation of oxygen free radicals (OFR) and tissue infiltration by activated neutrophils are consequences of ischemia and reperfusion and known causative factors of tissue injury; to delineate their role in the reperfusion injury occurring after cold preservation of the intestine and subsequent transplantation was the aim of this study. Prior to orthotopic SBTx in Sprague-Dawley rats, grafts were stored in cold (4 degrees C) Ringer's lactate solution for 1 (n=6), 2 (n=7), and 4 hr (n=7). Small bowel biopsy specimens were obtained before harvesting, at the end of the (cold) ischemic period and immediately before unclamping (i.e., before revascularization) and 30, 60, 120 min, and 24 hr after transplantation to evaluate tissue injury by histology, OFR production, (measured by luminol-enhanced chemiluminescence [LCL]), and the degree of neutrophil infiltration by myeloperoxidase staining. Reperfusion of the graft significantly worsened the histologically graded mucosal injury compared with that seen before unclamping. However, 24 hr after engraftment, mucosal morphology was restored almost completely. OFR production increased significantly during the early phases of reperfusion (30, 60, and 120 min) and returned to control values after 24 hr. Reperfusion of the graft was associated with a marked increase in the number of mucosal neutrophils. The present study indicates that OFR production and neutrophilic infiltration commence and progressively increase with graft reperfusion. These changes parallel the mucosal injury. Ischemic intervals of 4 hr were not associated with a statistically significant greater ischemic-injury patterns compared with 1- and 2-hr intervals. The profound changes associated with reperfusion probably overshadow the minor, yet likely, progressive injury patterns associated with longer ischemia times.

The effect of transplantation on small intestinal absorption, digestive capacity, myoelectric activity, and morphology was assessed in inbred Lewis rats. Electrodes were sutured to the duodenum and isografted jejunoileum or to the native jejunoileum in controls. The frequency of migrating myoelectric complexes (MMCs) in the duodenum was 3.3 +/- 0.3/hr in controls and 1.8 +/- 0.4/hr in transplants (P < 0.05). MMC frequency in the jejunoileum was 5.1 +/- 1.3/hr in controls and 3.2 +/- 0.9/hr in transplants (P > 0.05). MMCs appeared to migrate from the duodenum to the jejunoileum 80 +/- 3% of the time in controls and 59 +/- 7% of the time in transplant rats (P < 0.05). Absorption in the transplanted jejunoileum demonstrated a 35-40% decrease in glucose and electrolytes absorption. Villus height and number of nuclei per villus was reduced. Intestinal length (dry) was 103 +/- 6 cm for controls and 51 +/- 3 cm for transplant rats (P < 0.05). Brush border sucrase activity was unchanged. We conclude that small intestinal isografts display similar myoelectric activity as controls, but the decreased absorptive capacity and villus height may require longer segments of intestine to be transplanted in order to support normal nutrition.

Gram-negative septic episodes are a potential risk of small-bowel transplantation; bacterial translocation through the graft is considered the mechanism. As a measure to prevent this complication, we evaluated postoperative selective bowel decontamination (SBD) in the rat model of orthotopic small-bowel transplantation [Lewis (LEW) and Brown-Norway (BN) rats as donors and recipients]. For 4 days after transplantation we gave FK 506, 2 mg/kg, which prevents rejection and results in indefinite recipient survival. For SBD, 24 mg/kg/day polymyxin E and 20 mg/kg/day tobramycin were administered via orogastric gavage to allograft recipients, both with and without FK 506 therapy. On Day 9, all rats were sacrificed, the peritoneal cavity was swabbed, and mesenteric lymph nodes (MLN), spleen, liver, and ileum were harvested for microbial qualitative and quantitative analysis. Animals with positive peritoneal swab cultures were excluded. SBD resulted in a significant reduction of the quantitative gram-negative bacterial flora in the ileum and cecum and of bacterial translocation to the MLN [0% versus 50% (no FK 506 therapy) and 8% versus 50% (FK 506 treated)]. In the allograft groups not treated with FK 506, SBD failed to significantly prolong survival, suggesting that acute rejection is not hastened by infection (bacterial translocation). We conclude that SBD in small-bowel-graft recipients prevents bacterial translocation by reducing intestinal gram-negative bacterial flora; this may reduce local and systemic infections by gut-derived organisms.

Patients with chronic ulcerative colitis (CUC) are known to have decreased spontaneous IgA secretion by colonic mononuclear cells. The aim of this study was to determine whether a similar alteration exists in the apparently healthy ileum of patients with CUC. The concentration of IgA was measured in the supernatant from homogenized mucosal ileal biopsies using a sandwich-type ELISA. The concentration of IgA was significantly (P = 0.025) decreased in the ileum of patients with CUC (N = 24) in comparison to normal ileum (N = 10). The number of mucosal IgA-containing mononuclear cells (MNC) was also determined using an avidin-biotin-immunoperoxidase technique on paraffin-embedded ileal sections. Although reduced, the number of positive cells and their distribution was not significantly different in the ileum of patients with CUC (N = 20) when compared to normal ileum (N = 10). We suggest that decreased mucosal IgA levels are a panintestinal condition in CUC and that this is a primary alteration rather than a secondary response to the inflammatory process. Considering the role of IgA, we propose that decreased mucosal IgA levels in CUC may predispose to the disease by a reduction of the immune-mediated exclusion mechanism and/or by an impairment of the down-regulation of the inflammatory response.

We have previously demonstrated that subclinical chronic rejection (CR) induces structural and functional alterations in enteric smooth muscle and nerves in a rat model of small intestinal transplantation. This study was designed to investigate the effect of prolonged FK506 rescue therapy on these sequelae of CR. Immunohistochemistry of BrdU-labeled muscle cells demonstrated that active proliferation of intestinal smooth muscle caused by CR was successfully aborted by FK506 rescue therapy after a period of 30 days (control = 0.14 +/- 0.09; CR = 30.4 +/- 1.73; rescue = 2.4 +/- 0.63 cells/jejunal cross-section, P < 0.01). However, FK506 did not reverse the already established increase in muscular thickness (control = 92 +/- 2.4; CR = 193 +/- 10.6; rescue = 188 +/- 8.1 microns) due to CR. Bethanechol stimulated circular muscle contractility was improved markedly with rescue therapy (maximal contractile force reached 39.5% of control values in CR grafts and 68.8% after rescue). Rescue therapy did not reverse the loss of NADPH-diaphorase positive myenteric ganglia (control = 37 +/- 1.4; CR = 28 +/- 2.9; rescue = 23 +/- 1.7 ganglia/cross-section). Despite the persistent loss of ganglia, inhibitory junction potentials (IJPs) improved significantly returning to control values with FK506 (control = 10 +/- 0.5; CR = 5 +/- 0.3; CR rescue = 10 +/- 0.7 mV; IJPs recorded at 1 pulse/150V/0.75 ms). Although structural changes in enteric smooth muscle and myenteric neurons induced by CR were not reversed, the progression of subclinical CR can be effectively curbed by FK506 rescue therapy. The improvement in muscular mechanics and inhibitory neural innervation is probably due to the cessation of infiltrating immunocytes and sprouting of remaining myenteric nerves.

Advances in medical and surgical technique and the development of home parenteral nutrition have led to an increasing number of patients with short-bowel syndrome. Many patients could benefit from definite surgical therapy as long-term parenteral nutrition besides being expensive frequently causes severe complications. Various techniques to prolongate intestinal transit and increase the absorptive area of the remaining small bowel have been experimentally developed and some have been successfully employed in humans. The recent discovery of new potent immunosuppressive agents has initiated clinical endeavours at intestinal transplantation. The various techniques for the surgical therapy of short-bowel syndrome with their indications and potential risks are reviewed.

The effects of nitric oxide (NO) during small bowel preservation and reperfusion were studied in a rat model of heterotopic, syngeneic LEW-->LEW transplantation. A 6-hr preservation interval was chosen, which leads consistently to moderate graft injury permitting graft and recipient survival. To evaluate the function of NO during preservation and reperfusion, two inhibitors (NitroG-L-arginine methyl ester [L-NAME] and NG-monomethyl-L-arginine [NMA]) were administered and compared with a transplanted group receiving no treatment. The extent of preservation and reperfusion injury were delineated by histologic study and by the measurement of mucosal glutaminase on tissue specimens obtained 20 min after revascularization and 24 hr and 4 weeks postoperatively. Serum and mucosal NO(2-)+NO3- levels were determined at the same time points. Graft function and survival was inferior in all cases where NO production was inhibited. When recipients were treated with NO inhibitors, graft function and survival was more impaired when L-NAME was administered compared with NMA administration. Donor and graft pretreatment with NO inhibitors impaired graft function but not survival, and was less detrimental than recipient treatment. Mucosal NO(2-)+NO3- levels significantly increased in untreated transplanted animals 20 min after reperfusion. This increase was abolished in groups treated with NO inhibitors. Serum NO(2-)+NO3- levels increased significantly after 24 hr, and this increase was even more pronounced when NO inhibitors were administered. Furthermore, liver function deteriorated after inhibition of NO, indicating a more severe inflammatory response of the recipient after NO inhibition. These data indicate that mucosal NO production within the graft during preservation, and especially during reperfusion, has beneficial effects, but increased serum NO(2-)+NO3- levels coincided with inferior graft condition due to preservation and reperfusion injury.

The recent success in controlling acute rejection in clinical small bowel transplantation has resulted in a number of patients with functioning grafts and an occasional occurrence of graft-versus-host disease (GVHD). To better understand this complication following small bowel transplantation, a model of chronic GVHD was developed, using the Brown Norway-->Lewis rat strain combination. When the Lewis recipients were immunocompromised at the time of transplantation and received a graft specifically sensitized against Lewis, fatal GVHD developed in 3 of 5 animals. Serial histologic evaluation and determination of donor major histocompatibility complex (MHC) class I antigens were used to delineate the course of GVHD. Although the histologic results were inconsistent, with the exception of the animals developing fatal GVHD, the detection of donor MHC antigens correlated well with the development of GVHD. Determination of donor MHC class I antigens may serve as useful indicators for the development of GVHD.

The aim of the study was to delineate the most optimal preservation conditions for small bowel grafts. Established preservation solutions such as EuroCollins, University of Wisconsin, histidine-tryptophane-ketoglutarate-Brettschneider, phosphate-buffered sucrose (PBS 140), and 3 new solutions--extracellular fluid (ECF), lactobionate fructose, and a modified lactobionate fructose solution--were compared with saline to determine the most optimal solution for the intestine. Recipient survival, standard histology, and glutaminase activity were used to assess the degree of injury encountered after 12 hr of preservation followed by transplantation. To evaluate the various preservation conditions, ECF was used at pH 6.8 (original ECF). Grafts were preserved most optimally when a vascular washout after the cold storage period was omitted and when topical rewarming of the graft with 37 degrees C saline before reperfusion was performed. Graft survival was not significantly different after preservation with any solution tested (50-83%). Highest graft survival (83%) was achieved with lactobionate fructose and PBS140. Histologic evaluation 20 min after reperfusion revealed minor differences between most groups; a slight advantage was observed for PBS140-preserved grafts. Mucosal glutaminase activity of PBS140-preserved grafts was significantly higher 20 min after reperfusion compared with any other solution evaluated, indicating a superior graft function. These data indicate that different preservation conditions have a great impact on postoperative graft survival and that PBS140 might be preferable to any of the other preservation solutions tested.