Short bowel syndrome

Crisis in the gut: navigating gastrointestinal challenges in Gulf War Illness with bioengineering

Gulf War Illness (GWI) is characterized by a wide range of symptoms that manifests largely as gastrointestinal symptoms. Among these gastrointestinal symptoms, motility disorders are highly prevalent, presenting as chronic constipation, stomach pain, indigestion, diarrhea, and other conditions that severely impact the quality of life of GWI veterans. However, despite a high prevalence of gastrointestinal impairments among these veterans, most research attention has focused on neurological disturbances. This perspective provides a comprehensive overview of current in vivo research advancements elucidating the underlying mechanisms contributing to gastrointestinal disorders in GWI. Generally, these in vivo and in vitro models propose that neuroinflammation alters gut motility and drives the gastrointestinal symptoms reported in GWI. Additionally, this perspective highlights the potential and challenges of in vitro bioengineering models, which could be a crucial contributor to understanding and treating the pathology of gastrointestinal related-GWI.

Ex vivo gut-hepato-biliary organ perfusion model to characterize oral absorption, gut-wall metabolism, pre-systemic hepatic metabolism and biliary excretion; application to midazolam

To date, characterization of the first-pass effect of orally administered drugs consisting of local intestinal absorption and metabolism, portal vein transport and hepatobiliary processes remains challenging. Aim of this study was to explore the applicability of a porcine ex-vivo perfusion model to study oral absorption, gut-hepatobiliary metabolism and biliary excretion of midazolam. Slaughterhouse procured porcine en bloc organs (n = 4), were perfused via the aorta and portal vein. After 120 min of perfusion, midazolam, atenolol, antipyrine and FD4 were dosed via the duodenum and samples were taken from the systemic- and portal vein perfusate, intestinal faecal effluent and bile to determine drug and metabolite concentrations. Stable arterial and portal vein flow was obtained and viability of the perfused organs was confirmed. After intraduodenal administration, midazolam was rapidly detected in the portal vein together with 1-OH midazolam (EG-pv of 0.16±0.1) resulting from gut wall metabolism through oxidation. In the intestinal faecal effluent, 1-OH midazolam and 1-OH midazolam glucuronide (EG-intestine 0.051±0.03) was observed resulting from local gut glucuronidation. Biliary elimination of midazolam (0.04±0.01 %) and its glucuronide (0.01±0.01 %) only minimally contributed to the enterohepatic circulation. More extensive hepatic metabolism (FH 0.35±0.07) over intestinal metabolism (FG 0.78±0.11) was shown, resulting in oral bioavailability of 0.27±0.05. Ex vivo perfusion demonstrated to be a novel approach to characterize pre-systemic extraction of midazolam by measuring intestinal as well as hepatic extraction. The model can generate valuable insights into the absorption and metabolism of new drugs.

Thyroid dysfunction due to trace element deficiency-not only selenium but also zinc

INTRODUCTION

Levels of serum selenium (Se) and zinc (Zn) decrease when total parental nutrition (TPN) is administered without trace element supplementation for just a few weeks. These trace elements are involved in thyroid hormone metabolism and their deficiencies cause thyroid dysfunction. However, there have been few reports on the details of its clinical course.

CASE PRESENTATION

A 50-year-old man presented with thyroid dysfunction due to Se and Zn deficiency. He had an approximately 70-cm residual small intestine after undergoing intestinal resection and he received TPN without trace element supplementation for one and a half months. Blood tests revealed high levels of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) and low levels of free triiodothyronine (FT3). An abnormal pattern of thyroid function led to suspicion of Se deficiency. Se supplementation raised FT3 levels and lowered FT4 levels to within their respective reference ranges; however, subclinical hypothyroidism persisted with transient TSH elevation. We suspected that Zn deficiency also contributed to the hypothyroidism and, therefore, initiated Zn supplementation, which resulted in normalization of thyroid function.

DISCUSSION

Although thyroid dysfunction has been reported in many studies conducted on Se and Zn deficiencies, hormonal patterns vary between reports. Further accumulation of cases, including detailed data on nutritional status, would be of benefit to elucidate the clinical reality.

CONCLUSION

It is important to consider Se and Zn deficiencies when TSH and FT4 levels are elevated. It should also be noted that transient TSH elevation may be observed with Se supplementation.

A Transformable Mucoadhesive Microgel Network for Noninvasive Multimodal Imaging And Radioprotection of a Large Area of the Gastrointestinal Tract

The lack of noninvasive imaging and modulation of a large area of the gastrointestinal (GI) tract constrain the diagnosis and treatment of many GI-related diseases. Recent advances use novel mucoadhesive materials to coat a part of the GI tract and then modulate its functions. High mucoadhesion is the key factor of the partial coating, but also the limitation for not spreading and covering the lower GI tract. Here, a bismuth-pectin organic-inorganic hybrid complex is screened and engineered into a transformable microgel network (Bi-GLUE) with high flowability and mucoadhesion, such that it can quickly transit through and coat a large area of the GI tract. In murine and porcine models, Bi-GLUE delivers contrast agents to achieve real-time, large-area GI-tract imaging under X-ray or magnetic resonance  modalities and to facilitate the non-invasive diagnosis of familial adenomatous polyposis. Moreover, Bi-GLUE, like an intracorporal radiation shield, decreases the radiotoxicity in a whole-abdomen irradiation rat model. This transformable microgel network offers a new direction that can modulate a large area of the GI tract and may have broad applications for GI-related conditions.

Influences of exocrine pancreatic insufficiency on nutrient digestibility, growth parameters as well as anatomical and histological morphology of the intestine in a juvenile pig model

In a pig model, pancreatic duct ligation (PL) leads to a complete loss of exocrine function, causing an exocrine pancreatic insufficiency (EPI) without affecting endocrine function, allowing research of clinical effects and therapy options. This study aimed to investigate effects of experimentally induced EPI in juvenile pigs on digestion and intestinal morphology. Eight female juvenile cross-bred pigs (BW 54.8 kg at the start of the study) were included. Three animals were considered as a control (CON group), and in five animals the ductus pancreaticus accessorius was ligated (PL group). During the 10-week trial period, body weight and body measurements were recorded regularly. At the end of the trial, gastrointestinal tract (GIT) was investigated macroscopically and histologically and weight and digesta samples of individual segments were obtained. The pigs in the CON showed a significantly higher apparent total tract digestibility of crude protein and crude fat (87.8 and 79.9%, respectively) compared to PL (52.4 and 16.6%, respectively). Significant differences were noted in relative weights of duodenum, jejunum and colon (with and without digesta) and also in absolute weights of jejunum and colon. The mean number of nuclei in the transverse section in stratum circulare were significantly higher in all intestinal segments in CON compared to PL. Overall, EPI results in impaired nutrient digestibility with a greater filling of the GIT with digesta. The elongation of the small intestine does not represent "stretching" of the intestine, but rather increased synthesis of intestinal tissue.

First Registry of Adult Patients with Chronic Intestinal Failure due to Short Bowel Syndrome in Argentina, the RESTORE Project

BACKGROUND

Short-bowel syndrome (SBS) is considered a low prevalence disease. In Argentina, no registries are available on chronic intestinal failure (CIF) and SBS. This project was designed as the first national registry to report adult patients with this disease.

METHODS

A prospective multicenter observational registry was created including adult patients with CIF/SBS from 8/12 approved centers. Demographics, clinical characteristics, nutritional assessment, home-parenteral-nutrition (HPN) management plus complications, surgeries performed, medical treatment, overall survival, and freedom from HPN survival were analyzed.

RESULTS

Of the 61 enrolled patients, 56 with available follow up data were analyzed. At enrollment, the mean intestinal length was 59.5±47.3cms; the anatomy was: type 1 (n=41), type 2 (n=10), and type 3 (n=5). At the end of the interim analysis, anatomy changed to type 1 in 31, type 2 in 17, and type 3 in 8 patients. The overall mean time on HPN before enrollment was 33.5±56.2 months. Autologous gastrointestinal-reconstruction surgery was performed before enrollment on 21 patients, and afterward on 11. Nine patients (16.1%) were weaned-off HPN with standard medical-nutritional treatment; 12 patients received enterohormones, and 2 of them suspended HPN; 1 was considered a transplant candidate. In 23.7±14.5 months, 11 out of 56 patients discontinued HPN; Kaplan-Meier freedom from HPN survival was 28.9%. The number of cases collected represented 19.6 new adult CIF/SBS patients/year.

CONCLUSIONS

The RESTORE project allowed us to know the incidence, the current medical and surgical management of this pathology, as well as its outcome and complications related with the therapeutic approach currently available.

CLINICAL RELEVANCY STATEMENT

RESTORE is the first ongoing prospective, observational, epidemiological, multicenter registry of adult patients with chronic intestinal failure (CIF) due to short bowel syndrome (SBS) in Argentina. The interim analysis enabled an estimate of the incidence of adult CIF/SBS of 19.6 new adult CIF/SBS patients/year in our country and would serve for a better understanding of the current care provided, the manner to continue improving that condition, the current treatment outcomes, and a more accurate definition of the national needs. This article is protected by copyright. All rights reserved.

Serial transverse enteroplasty and nipple valve construction, two life saving techniques for patients with short bowel syndrome, a report of 5 cases

Background

Various abdominal pathologies end up with surgical resection of small intestine. When the small intestine remnant is too short for adequate fluid and micronutrients absorption, short bowel syndrome is diagnosed. The disabling condition needs a multidisciplinary approach to design parenteral nutrition, care for thrombotic, hepatic and infectious complications and gradually wean the patient from parenteral nutrition. Various surgical techniques have been introduced to increase absorptive mucosa and enhance the intestinal adaptation process. Serial transverse enteroplasty and nipple valve reconstruction are among the procedures, which will be discussed in the current article.

Case presentation

Herein, we presented 5 cases of short bowel syndrome as a consequence of abdominal laparotomies, patients were referred to our center to receive parenteral nutrition and to be prepared for the final autologous gastrointestinal reconstruction or intestinal transplantation, if indicated.

Conclusion

Patient’s age, performance status and bowel remnant length determines the appropriate technique for autologous gastrointestinal reconstruction. Serial transverse enteroplasty is designed to increase bowel’s length by creating zigzag patterns through dilated bowel loops. Presence of ileocecal valve is crucial to delay intestinal transit time and to prevent colonic bacterial transfer to ileum. Patient’s with ileocecal valve loss benefit from creating an artificial valve, namely, nipple valve.

Consideration of Intestinal Failure in Cases of De-Adaptation of Short Bowel Syndrome: A Case Report and Descriptive Review

Short bowel syndrome (SBS) causes malabsorption due to extensive intestinal resection. While intestinal function declines with age, little is known about the relationship between intestinal failure and ageing. For the first time in Japan, we report a case of de-adaptation of SBS thought to be due to ageing, in a 93-year-old woman who presented with electrolyte imbalance and malnutrition. She had undergone five surgical resections of the small intestine over the past 20 years. She had developed SBS once due to multiple surgeries, but due to compensatory function, the symptoms had abated. However, due to decreased intestinal function caused by ageing, it worsened and symptoms reappeared. A literature search for the period January 1990 to May 2021 in Ichushi a major journal in Japan, found that de-adaptation of SBS occurred in 23 previous cases, of which we were able to confirm the details in 17 cases, with no case reports on “de-adaptation of SBS”, demonstrating that the concept of “intestinal failure” has only recently begun to be used in routine practice. Therefore, we stress the importance of re-emphasizing the concept of ”intestinal failure” in everyday practice, as well as other organ-related conditions such as cardiac or renal failure, as this may lead to a better understanding of the pathogenesis of malnutrition and diarrhoea in elderly patients.

Approach to the adult patient with chronic diarrhea: A literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

Approach to the adult patient with chronic diarrhea: a literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

Effectiveness of Intraoperative Indocyanine Green Fluorescence-Navigated Surgery for Superior Mesenteric Vein Thrombosis that Developed During Treatment for Intravascular Lymphoma: A Case Report

BACKGROUND Superior mesenteric vein thrombosis (SMVT) is a relatively rare form of acute abdominal disease; less than 0.1% of laparotomy surgeries are performed for SMVT. In the presence of severe intestinal ischemia or necrosis caused by SMVT, immediate surgical intervention is required. Macroscopic diagnosis of intestinal viability is sometimes difficult; its over-resection may carry the risk of short bowel syndrome. A near-infrared fluorescence imaging system with indocyanine green (ICG) has recently been developed for intraoperative, real-time evaluation of intestinal perfusion. This is the first report on the use of ICG fluorescence imaging during surgery for intestinal ischemia caused by venous thrombosis. CASE REPORT A 70-year-old man presented with a general feeling of weariness. On examination, he was diagnosed with intravascular large B cell lymphoma. R-CHOP therapy was initiated. On day 3 of initial R-CHOP therapy, the patient experienced sudden severe abdominal pain while in the hospital. Contrast-enhanced computed tomography revealed SMVT and loss of contrast effect in the small intestine. We diagnosed small bowel necrosis caused by SMVT, and exploratory laparotomy was performed, which revealed a continuous ischemia of 150 cm. Intraoperative ICG fluorescence imaging was utilized, and the color boundary was consistent with the ischemic area detected by visualization. The necrotic small intestine was excised and anastomosed. The patient was transferred to the hematology department on postoperative day 10 with no severe complications such as anastomotic leakage or re-thrombosis, and re-embolization was not observed 6 months later. CONCLUSIONS Venous thrombosis should be listed as a differential diagnosis when acute abdominal disease presents during chemotherapy for malignant lymphoma. ICG fluorescence imaging may be useful in the evaluation of intestinal blood flow for venous thrombosis.

Increased intestinal permeability in patients with short bowel syndrome is not affected by parenteral nutrition

The aim of our study was to assess the presence and degree of intestinal leakage in subjects suffering from short bowel syndrome (SBS) and its modification by parenteral nutrition. To this end we assessed circulating levels of selected makers of intestinal permeability including zonulin, fatty acid binding protein 2 (FABP-2), citrulline and glucagon-like peptide 2 (GLP-2). We also measured lipopolysaccharide binding protein (LBP) as a marker of circulating levels of lipopolysaccharide acting through the CD14 molecule. Eleven SBS and 10 age- and BMI-matched control subjects were included into the study. The effect of parenteral nutrition was assessed after 14 days, 6 and 12 months from its initiation, respectively. At baseline, SBS patients had increased gut permeability as measured by zonulin (47.24+/-2.14 vs. 39.48+/-1.20 ng/ml, p=0.006) and LBP (30.32+/-13.25 vs. 9.77+/-0.71 microg/ml, p<0.001) compared to healthy controls. Furthermore, SBS subjects had reduced FABP-2, unchanged citrulline and increased sCD14 and GLP-2 relative to control group. Throughout the whole study period the administered parenteral nutrition had no significant effect on any of the studied parameters. Taken together, our data show that patients with short bowel syndrome have increased intestinal permeability that is not affected by parenteral nutrition.

Successful management of adhesion related small bowel ischemia without intestinal resection: A case report and review of literature

BACKGROUND

Intraabdominal adhesions develop spontaneously or after an inflammatory process or surgical procedure in the abdomen. They are the most common cause of small bowel obstruction (SBO). SBO occasionally leads to intestinal ischemia (InIs) which can be a life-threatening condition that requires management as soon as possible. We herein report a case of SBO with InIs presented in our institution and treated without intestinal resection.

CASE SUMMARY

A 34-year-old man presented at the emergency department after a 12-h-onset diffuse abdominal pain, bloating and nausea. He had a history of traumatic right hepatectomy 11 years ago as well as adhesiolysis and resection of a long part of small bowel 2 years ago. An abdominal computed tomography (CT) showed dilated loops that led to the diagnosis of SBO. Due to deteriorating lactic acidosis, the patient was operated. Torsion of the small bowel around an adhesion led to 2.30 m of ischemic ileum. After the application of N/S 40 °C for 20 min, the intestine showed signs of improvement and it was decided to avoid resection and instead temporary close the abdomen with vacuum-pack technique. At the second-look laparotomy 48 h later, the intestine appeared normal. The patient was discharged on the 8th post-op day in excellent condition.

CONCLUSION

In case of SBO caused by adhesions, extreme caution is needed if InIs is present, as the clinical signs are mild and you should rely for diagnosis in CT findings and lactate levels. Conservative surgical approach could reverse the effects of InIs, if performed quickly, so that intestinal resection is avoided and should be used even when minimum signs of viability are present.

Bioengineering functional smooth muscle with spontaneous rhythmic contraction in vitro

Oriented smooth muscle layers in the intestine contract rhythmically due to the action of interstitial cells of Cajal (ICC) that serve as pacemakers of the intestine. Disruption of ICC networks has been reported in various intestinal motility disorders, which limit the quality and expectancy of life. A significant challenge in intestinal smooth muscle engineering is the rapid loss of function in cultured ICC and smooth muscle cells (SMC). Here we demonstrate a novel approach to maintain the function of both ICC and SMC in vitro. Primary intestinal SMC mixtures cultured on feeder cells seeded electrospun poly(3-caprolactone) scaffolds exhibited rhythmic contractions with directionality for over 10 weeks in vitro. The simplicity of this system should allow for wide usage in research on intestinal motility disorders and tissue engineering, and may prove to be a versatile platform for generating other types of functional SMC in vitro.

Distal Bowel Re-feeding in Patients with Proximal Jejunostomy

BACKGROUND

Patients who have a proximal jejunostomy are difficult to manage because of their high stoma output which results in fluid and electrolyte imbalance with repeated hospital admissions and the necessity for expensive parenteral nutrition (PN). There are few reports on the use of re-feeding of the proximal effluents in this situation.

METHODS

We here relate our experience with this manoeuvre in 35 patients between Jan 2010 and Feb 2016 who had stomas less than 120 cm away from the duodenojejunal flexure.

RESULTS

There were 26 males and 9 females, whose median age was 47 (19-74) years. The most common indications for massive bowel resection were gangrene in 25 (71%) and intestinal perforation in 7 (20%). The median proximal and distal small bowel lengths were 45 (15-120) cm and 90 (0-240) cm respectively. The ileocaecal (IC) valve was preserved in 33 (94%) and there was only colon distally (without the ileocaecal valve) in 2 (6%) patients. Twenty-five (71%) patients required post-operative ICU care. Additional PN was required in 6 (17%) patients during their index admission with the average extra cost of treatment being 20,000 rupees. Their median hospital stay was 13 (6-60) days. Patients were discharged without intravenous (IV) lines. Eight (26%) patients required re-admission for acute renal failure which was managed conservatively. No major problems were associated with re-feeding. None of the patients required PN after discharge from hospital. Thirty (86%) patients had their stomas closed at 65 (14-224) days. Both the patients with colon only as their distal bowel remnant died. Sepsis was the cause of mortality in 4 (11%) during index admission and 3 after their discharge. On follow-up after bowel re-connection, 2 patients died after 1 and 12 months, both due to intracranial bleeding, and the overall survival was 74%.

CONCLUSIONS

Patients with proximal jejunostomies can be managed with distal re-feeding. It is a cost-effective and effective substitute for PN, is associated with few problems, and has a fairly good long-term outcome.

Modified Paul-Mikulicz jejunostomy in frail geriatric patients undergoing emergency small bowel resection

BACKGROUND

Proximal or extended bowel resections are sometimes necessary during emergency surgery of the small bowel and call for creating a high small bowel stomy as a part of damage control surgery. Secondary restoration of intestinal continuity in the frail geriatric patient, further weakened by subsequent severe malabsorption may be prohibitive.

METHODS

Six patients underwent emergency small bowel resection for proximal jejunal disease (83.3% high-grade adhesive SBO and 16.7% jejunal diverticulitis complicated with perforation). With the intention to avoid end jejunostomy and the need for repeat laparotomy for bowel continuity restoration we modified the classic Paul-Mikulicz jejunostomy.

RESULTS

The postoperative course was uneventful in four patients whose general condition improved considerably. At six-month follow-up, neither patients required parenteral nutrition.

CONCLUSIONS

This modified stoma can have the advantage of allowing a partial passage of the enteric contents, reducing the degree of malabsorption, and rendering jejunostomy reversal easy to perform later.

Linking stem cell function and growth pattern of intestinal organoids

Intestinal stem cells (ISCs) require well-defined signals from their environment in order to carry out their specific functions. Most of these signals are provided by neighboring cells that form a stem cell niche, whose shape and cellular composition self-organize. Major features of this self-organization can be studied in ISC-derived organoid culture. In this system, manipulation of essential pathways of stem cell maintenance and differentiation results in well-described growth phenotypes. We here provide an individual cell-based model of intestinal organoids that enables a mechanistic explanation of the observed growth phenotypes. In simulation studies of the 3D structure of expanding organoids, we investigate interdependences between Wnt- and Notch-signaling which control the shape of the stem cell niche and, thus, the growth pattern of the organoids. Similar to in vitro experiments, changes of pathway activities alter the cellular composition of the organoids and, thereby, affect their shape. Exogenous Wnt enforces transitions from branched into a cyst-like growth pattern; known to occur spontaneously during long term organoid expansion. Based on our simulation results, we predict that the cyst-like pattern is associated with biomechanical changes of the cells which assign them a growth advantage. The results suggest ongoing stem cell adaptation to in vitro conditions during long term expansion by stabilizing Wnt-activity. Our study exemplifies the potential of individual cell-based modeling in unraveling links between molecular stem cell regulation and 3D growth of tissues. This kind of modeling combines experimental results in the fields of stem cell biology and cell biomechanics constituting a prerequisite for a better understanding of tissue regeneration as well as developmental processes.

Chronic Diarrhea: Diagnosis and Management

Chronic diarrhea is a common problem affecting up to 5% of the population at a given time. Patients vary in their definition of diarrhea, citing loose stool consistency, increased frequency, urgency of bowel movements, or incontinence as key symptoms. Physicians have used increased frequency of defecation or increased stool weight as major criteria and distinguish acute diarrhea, often due to self-limited, acute infections, from chronic diarrhea, which has a broader differential diagnosis, by duration of symptoms; 4 weeks is a frequently used cutoff. Symptom clusters and settings can be used to assess the likelihood of particular causes of diarrhea. Irritable bowel syndrome can be distinguished from some other causes of chronic diarrhea by the presence of pain that peaks before defecation, is relieved by defecation, and is associated with changes in stool form or frequency (Rome criteria). Patients with chronic diarrhea usually need some evaluation, but history and physical examination may be sufficient to direct therapy in some. For example, diet, medications, and surgery or radiation therapy can be important causes of chronic diarrhea that can be suspected on the basis of history alone. Testing is indicated when alarm features are present, when there is no obvious cause evident, or the differential diagnosis needs further delineation. Testing of blood and stool, endoscopy, imaging studies, histology, and physiological testing all have roles to play but are not all needed in every patient. Categorizing patients after limited testing may allow more directed testing and more rapid diagnosis. Empiric antidiarrheal therapy can be used to mitigate symptoms in most patients for whom a specific treatment is not available.

Intestinal Failure: New Definition and Clinical Implications

Intestinal failure (IF) is a state in which the nutritional demands of the body are not met by the gastrointestinal absorptive surface. It is a long-recognized complication associated with short bowel syndrome, which results in malabsorption after significant resection of the intestine for many reasons or functional dysmotility. Etiologies have included Crohn's disease, vascular complications, and the effects of radiation enteritis, as well as the effects of intestinal obstruction, dysmotility, or congenital defects. While IF has been long-recognized, it has historically not been uniformly defined, which has made both recognition and management challenging. This review examines the previous definitions of IF as well as the newer definition and classification of IF and how it is essential to IF clinical guidelines.

Intestinal Failure: Adaptation, Rehabilitation, and Transplantation

Intestinal failure (IF) is a state in which the nutritional demands are not met by the gastrointestinal absorptive surface. A majority of IF cases are associated with short-bowel syndrome, which is a result of malabsorption after significant intestinal resection for numerous reasons, some of which include Crohn's disease, vascular thrombosis, and radiation enteritis. IF can also be caused by obstruction, dysmotility, and congenital defects. Recognition and management of IF can be challenging, given the complex nature of this condition. This review discusses the management of IF with a focus on intestinal rehabilitation, parenteral nutrition, and transplantation.

Assessment of energy requirements in patients with short bowel syndrome by using the doubly labeled water method

BACKGROUND

Short bowel syndrome (SBS) is a serious malabsorption disorder, and dietetic management of patients with SBS is extremely challenging. Once the degree of undernutrition has been assessed, successful dietary intervention is contingent on an accurate estimation and provision of energy needs.

OBJECTIVE

We quantified total energy expenditure (TEE) in patients with SBS by using the doubly labeled water (DLW) method to inform energy needs and nutritional therapy goals.

DESIGN

In this observational study, TEE was measured in 22 participants, 11 with SBS and 11 sex-, age-, and body mass index (BMI)-matched controls (non-SBS), for 14 d with the DLW method. Predicted energy requirements were determined by using the Escott-Stump equation and compared with TEE determined with DLW. Resting energy expenditure was measured by using indirect calorimetry, and an accelerometer was also used to determine physical activity level.

RESULTS

Participants were aged (mean ± SD) 53 ± 8 y. Measured TEE was significantly higher than predicted TEE for the SBS group (1875 ± 276 compared with 1517 ± 175 kcal/d, P = 0.001) and also for the non-SBS group (2393 ± 445 compared with 1532 ± 178 kcal/d, P < 0.01). Measured TEE was significantly lower in the SBS group than in the non-SBS group (P < 0.01); however, predicted TEE did not differ significantly between the groups (P = 0.84). No significant differences were seen between measured and predicted resting energy expenditure either within or between groups.

CONCLUSIONS

Measured TEE in patients with SBS was significantly higher than predicted by using standard equations but also lower than values for age-, BMI-, and sex-matched non-SBS controls. Currently used formulas in clinical practice appear to underestimate energy requirements of patients with SBS, and revision is needed to prevent underfeeding and improve long-term prognosis. This trial was registered at clinicaltrials.gov as NCT02113228.

Outcomes of Patients with Intestinal Failure after the Development and Implementation of a Multidisciplinary Team

Aim. A multidisciplinary team was created in our institution to manage patients with intestinal failure (INFANT: INtestinal Failure Advanced Nutrition Team). We aimed to evaluate the impact of the implementation of the team on the outcomes of this patient population. Methods. Retrospective chart review of patients with intestinal failure over a 6-year period was performed. Outcomes of patients followed up by INFANT (2010-2012) were compared to a historical cohort (2007-2009). Results. Twenty-eight patients with intestinal failure were followed up by INFANT while the historical cohort was formed by 27 patients. There was no difference between the groups regarding remaining length of small and large bowel, presence of ICV, or number of infants who reached full enteral feeds. Patients followed up by INFANT took longer to attain full enteral feeds and had longer duration of PN, probably reflecting more complex cases. Overall mortality (14.8%/7.1%) was lower than other centers, probably illustrating our population of "early" intestinal failure patients. Conclusions. Our data demonstrates that the creation and implementation of a multidisciplinary program in a tertiary center without an intestinal and liver transplant program can lead to improvement in many aspects of their care.

Hypokalemia causing rhabdomyolysis in a patient with short bowel syndrome

BACKGROUND

Rhabdomyolysis, usually in the setting of trauma or drug use, is frequently seen in the emergency setting, and often leads to hyperkalemia at presentation. Hypokalemia, however, is a potentially underrecognized cause of rhabdomyolysis.

CASE REPORT

We present a case of rhabdomyolysis likely due to hypokalemia in the setting of short bowel syndrome. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although less common, hypokalemia can be a significant cause of rhabdomyolysis via its effects on muscle. This scenario should be considered in the differential diagnosis of patients at risk for hypokalemia who present with weakness. Rapid recognition of this relationship and rapid correction of hypokalemia may prove very important in preventing the deleterious effects of rhabdomyolysis.

Smooth muscle strips for intestinal tissue engineering

Functionally contracting smooth muscle is an essential part of the engineered intestine that has not been replicated in vitro. The purpose of this study is to produce contracting smooth muscle in culture by maintaining the native smooth muscle organization. We employed intact smooth muscle strips and compared them to dissociated smooth muscle cells in culture for 14 days. Cells isolated by enzymatic digestion quickly lost maturity markers for smooth muscle cells and contained few enteric neural and glial cells. Cultured smooth muscle strips exhibited periodic contraction and maintained neural and glial markers. Smooth muscle strips cultured for 14 days also exhibited regular fluctuation of intracellular calcium, whereas cultured smooth muscle cells did not. After implantation in omentum for 14 days on polycaprolactone scaffolds, smooth muscle strip constructs expressed high levels of smooth muscle maturity markers as well as enteric neural and glial cells. Intact smooth muscle strips may be a useful component for engineered intestinal smooth muscle.

A Short Bowel (Small Intestine = 40 cm), No Ileocecal Valve, and Colonic Inertia Patient Works Well with Oral Intake Alone without Parenteral Nutrition

We present a 50-year-old male who suffered from ischemic bowel disease, having undergone massive resection of small intestine and ileocecal valve. He had to cope with 40 cm proximal jejunum and 70 cm distal colon remaining. In the postoperative period parenteral nutrition (PN) was used immediately for nutrition support and electrolyte imbalance correction. We gave him home PN as regular recommendation for the short bowel status after discharge from hospital. This patient has tolerated regular oral intake 2 months later and did not develop significant short bowel syndrome. There were several episodes of venous access infection which troubled this patient and admitted him for treatment during home PN. Therefore, we changed home PN to cyclic tapering pattern. The patient could maintain his nutrition and hydration with oral intake alone after tapering home PN 15 months later. He has survived more than one year without PN support and still maintained 80% ideal body weight with average albumin of 3.5 ± 0.2 mg/dL. Although patient was hospitalized every two months to supplement nutrients, however, this has greatly improved the quality of life.

The effect of scaffold macroporosity on angiogenesis and cell survival in tissue-engineered smooth muscle

Angiogenesis and survival of cells within thick scaffolds is a major concern in tissue engineering. The purpose of this study is to increase the survival of intestinal smooth muscle cells (SMCs) in implanted tissue-engineered constructs. We incorporated 250-μm pores in multi-layered, electrospun scaffolds with a macroporosity ranging from 15% to 25% to facilitate angiogenesis. The survival of green fluorescent protein (GFP)-expressing SMCs was evaluated after 2 weeks of implantation. Whereas host cellular infiltration was similar in scaffolds with different macroporosities, blood vessel development increased with increasing macroporosity. Scaffolds with 25% macropores had the most GFP-expressing SMCs, which correlated with the highest degree of angiogenesis over 1 mm away from the outermost layer. The 25% macroporous group exceeded a critical threshold of macropore connectivity, accelerating angiogenesis and improving implanted cell survival in a tissue-engineered smooth muscle construct.

Spectrum of short bowel syndrome in adults: intestinal insufficiency to intestinal failure

Short bowel syndrome (SBS) refers to the malabsorptive state caused by physical or functional loss of portions of the small intestine, most commonly following extensive intestinal resection. Such resections hinder absorption of adequate amounts of macronutrients, micronutrients, electrolytes, and water, resulting in malnutrition, diarrhea, and dehydration. Clinical features of SBS vary along a continuum, depending on the extent and anatomy of intestine lost and the ability of the patient and the remaining intestine to compensate for the loss. The impact of SBS can be extensive, leading to diminished health-related quality of life because of its many physical and psychological effects on patients. SBS is associated with decreased survival; risk factors for SBS-related mortality include very short remnant small bowel, end-jejunal remnant anatomy, and arterial mesenteric infarction as primary cause. Although parenteral nutrition and/or intravenous fluid (PN/IV) is a life-saving measure for many patients with SBS, patients with the most severe malabsorption (ie, dependent on PN/IV) are at risk for severe, chronic complications and death. Patients' treatment needs vary depending on disease severity and resection type; thus, each patient should be individually managed. This review discusses the spectrum of disease in patients with SBS and presents common complications encountered by these patients to highlight the importance of individualized management and treatment.

Chronic radiation enteritis and malnutrition

Radiation enteritis is defined as the loss of absorptive capacity of the intestine following irradiation, which is most commonly seen after radiotherapy for pelvic and abdominal malignancies. It is divided into acute and chronic forms and usually presents with diarrhea and malabsorption. Malnutrition is a common complication of chronic radiation enteritis (CRE). We reviewed the etiology, prevalence, symptoms, diagnosis and management of CRE and CRE with malnutrition in this article. Functional short bowel syndrome as a cause of malnutrition in CRE is also considered. The diagnostic work-up includes serum markers, endoscopy, cross-sectional imaging and the exclusion of alternative diagnoses such as recurrent malignancy. Management options of CRE include dietary manipulation, anti-motility agents, electrolyte correction, probiotics, parenteral nutrition, surgical resection and small bowel transplantation. Treatment may also be required for coexisting conditions including vitamin B12 deficiency, bile acid malabsorption and depression.

Interleukin-17 plays a critical role in the acute rejection of intestinal transplantation

AIM: To investigate the role of interleukin (IL)-17 in small bowel allograft rejection.

METHODS: We detected the expression of helper T cell 17 (Th17) cells in biopsy specimens from 3 cases of living small bowel transplantation in our department through immunofluorescence stain. We then established a rat heterotopic small bowel transplantation model. The rats were sacrificed on the 1^st, 2^nd, 3^rd, 5^th, and 7^th d after small bowel transplantation. The degrees of transplantation rejection in rat intestine graft were examined through hematoxylin eosin (HE) stain, and the expression of Th17 cells in rat intestine graft were detected through immunofluorescence stain. In addition, the recipient rats undergoing intestinal transplantation were administrated with mouse-anti-rat IL-17 monoclonal antibody (mAb), and the survival of rats was analyzed. The recipient rats which received mouse-anti-rat IL-17 mAb treatment were sacrificed on the 1^st, 2^nd, 3^rd, 5^th, and 7^th d after small bowel transplantation. The degrees of transplantation rejection and the expression of Th17 cells in rat intestine graft were detected through HE and immunofluorescence stain. The expression of IL-17, IL-1β, tumor necroses factor receptor-α (TNF-α), IL-6, and IL-8 in the intestine graft or serum were also detected.

RESULTS: The expressions of Th17 cells ran parallel with the degree of acute rejection in human intestine grafts. The intestine graft rejection of rats was aggravated with prolonged duration after intestinal transplantation, and the expressions of Th17 cells were also correlated with the degree of acute rejection in rat intestine grafts. Administration of mouse-anti-rat IL-17 mAb prolonged the survival of rats after small bowel transplantation (P < 0.001). Furthermore, we found that the administration of mouse-anti-rat IL-17 mAb significantly decreased the intensity of CD4⁺IL-17⁺ Th17 cells in intestine grafts on the 2^nd, 3^rd, 5^th, and the 7^th d (97.22 ± 4.05 vs 12.45 ± 2.02 on the 7^th d, P < 0.0001), and suppressed the severity of acute rejection. The expression of IL-17 in the intestine graft declined after mouse-anti-rat IL-17 mAb administration on the 2^nd, 3^rd, 5^th, and the 7^th d (0.88 ± 0.03 vs 0.35 ± 0.02 on the 7^th d, P < 0.0001). We also detected the IL-17 serum level and found that the IL-17 level reduced from the 1^st d to the 7^th d (6.52 ± 0.18 ng/mL vs 2.04 ± 0.15 ng/mL on the 7^th d, P < 0.0001). No significant difference in the level of IL-17 mRNA in the intestine graft was identified between the two groups. The levels of IL-1β, TNF-α, IL-6, and IL-8 mRNA in the intestine graft after the administration of mouse-anti-rat IL-17 mAb were also tested. We found that on the 3^rd, 5^th, and 7^th d after intestinal transplantation, administration of mouse-anti-rat IL-17 mAb significantly inhibited the levels of IL-1β (12.11 ± 1.16 vs 1.27 ± 0.15 on the 7^th d, P < 0.001), TNF-α (27.37 ± 2.60 vs 1.06 ± 0.26 on the 7^th d, P < 0.001), IL-6 (21.43 ± 1.79 vs 1.90 ± 0.32 on the 7^th d, P < 0.001), and IL-8 (20.44 ± 1.44 vs 1.34 ± 0.20 on the 7^th d, P < 0.001) mRNA in the intestine graft.

CONCLUSION: IL-17 may act as a promising and potent target for inhibiting acute rejection after small bowel transplantation.

Avaliação e seguimento de pacientes adultos com síndrome do intestino curto pelo exame contrastado de trânsito intestinal

A síndrome do intestino curto é definida pela incapacidade da superfície do intestino delgado em manter as condições adequadas de absorção de nutrientes, ocasionando deficiências nutricionais. Em adultos, as principais causas de síndrome do intestino curto são as ressecções cirúrgicas amplas ou múltiplas, secundárias a infarto mesentérico, doença de Crohn e enterite actínica. Além de avaliar o tempo de trânsito até o intestino grosso, o exame contrastado de trânsito intestinal pode ser utilizado na medição da extensão do intestino remanescente e no acompanhamento dos fenômenos de adaptação estrutural das alças delgadas e colônicas. Em pacientes com síndrome do intestino curto, a adaptação estrutural do intestino delgado consiste na hiperplasia das vilosidades e das pregas mucosas, que se tornam mais numerosas, profundas e de maior diâmetro, assim como a dilatação do segmento remanescente. Esses achados morfológicos são mais pronunciados e bem estabelecidos nas alças ileais, evidenciando sua maior capacidade adaptativa. O conhecimento dos achados por imagem das características morfológicas e adaptativas do intestino delgado é de grande importância na abordagem multidisciplinar da síndrome do intestino curto.