The current status of small bowel transplantation in the UK and internationally

Factors that impact on the quality of life of intestinal failure patients treated with home parenteral nutrition: protocol for a multicentre, longitudinal observational study

BACKGROUND

Home parenteral nutrition (HPN) refers to the intravenous administration of macronutrients, micronutrients and fluid. The aims of treatment are to increase survival and improve quality of life (QoL). However, patients struggle with physiological symptoms, time-consuming invasive therapy and an increased occurrence of depression and social isolation. Our aim is to understand how HPN impacts the QoL of patients, and the contribution played by the complications of treatment, for example, liver disease.

METHODS AND ANALYSIS

A multicentre, longitudinal, observational study will be conducted using routinely collected clinical data. Participants will also be asked to complete three QoL questionnaires (EuroQol-5 Dimensions, Short Form 36 and HPN-QoL) at baseline and 12 months. The primary outcome is mean change in QoL scores over 12 months. Secondary outcomes include how factors including liver function, gut microbiota, number of infusions of PN per week, nutritional composition of PN and nutritional status impact on QoL scores.

ETHICS AND DISSEMINATION

Ethical approval was obtained from HRA and Health and Care Research Wales Research Ethics Committee (21/SC/0316). The study was eligible for portfolio adoption, Central Portfolio Management System ID 50506. Results will be disseminated through peer-reviewed scientific journals and presented at national and international meetings.

A metagenomic prospective cohort study on gut microbiome composition and clinical infection in small bowel transplantation

Two-thirds of small-bowel transplantation (SBT) recipients develop bacteremia, with the majority of infections occurring within 3 months post-transplant. Sepsis-related mortality occurs in 31% of patients and is commonly caused by bacteria of gut origin, which are thought to translocate across the implanted organ. Serial post-transplant surveillance endoscopies provide an opportunity to study whether the composition of the ileal and colonic microbiota can predict the emergence as well as the pathogen of subsequent clinical infections in the SBT patient population. Five participants serially underwent aspiration of ileal and colonic bowel effluents at transplantation and during follow-up endoscopy either until death or for up to 3 months post-SBT. We performed whole-metagenome sequencing (WMS) of 40 bowel effluent samples and compared the results with clinical infection episodes. Microbiome composition was concordant between participants and timepoint-matched ileal and colonic samples. Four out of five (4/5) participants had clinically significant infections thought to be of gut origin. Bacterial translocation from the gut was observed in 3/5 patients with bacterial infectious etiologies. In all three cases, the pathogens had demonstrably colonized the gut between 1-10 days prior to invasive clinical infection. Recipients with better outcomes received donor grafts with higher alpha diversity. There was an increase in the number of antimicrobial resistance genes associated with longer hospital stay for all participants. This metagenomic study provides preliminary evidence to support the pathogen translocation hypothesis of gut-origin sepsis in the SBT cohort. Ileal and colonic microbiome compositions were concordant; therefore, fecal metagenomic analysis could be a useful surveillance tool for impeding infection with specific gut-residing pathogens.

Decellularized small intestine scaffolds: a potential xenograft for restoration of intestinal perforation

Small intestine perforation is a serious medical condition that requires immediate medical attention. The traditional course of treatment entails resection followed by anastomosis; however, it has complications such as small bowel syndrome (SBS), anastomotic leakage, and fistula formation. Here, a novel strategy is demonstrated, that utilizes the xenogeneic, decellularized goat small intestine as a patch for small intestine regeneration in cases of intestinal perforation. The goat small intestine scaffold underwent sodium dodecyl sulfate decellularization, which revealed consistent, quick, and effective decellularization. Decellularization contributed the least amount of extracellular matrix degradation while maintaining the intestinal architecture. By implanting the decellularized goat small intestine scaffolds (DGSIS) on the chorioallantoic membrane (CAM), no discernible loss of angiogenesis was seen in the CAM region, and this enabled the DGSIS to be evaluated for biocompatibility in ovo. The DGSIS was then xeno-transplanted as a patch on a small intestine perforation rat model. After 30 days post transplant, barium salt used as contrast gastrointestinal X-ray imaging revealed no leakage or obstruction in the small intestine. Histology, scanning electron microscopy, and immunohistochemistry assisted in analyzing the engraftment of host cells into the xeno patch. The xeno-patch expressed high levels of E-cadherin, α-smooth muscle actin (α-SMA), Occludin, Zonnula occluden (ZO-1), Ki 67, and Na+/K+-ATPase. The xeno-patch was consequently recellularized and incorporated into the host without causing an inflammatory reaction. As an outcome, decellularized goat small intestine was employed as a xenograft and could be suitable for regeneration of the perforated small intestine.

BSHI and BTS UK guideline on the detection of alloantibodies in solid organ (and islet) transplantation

Solid organ transplantation represents the best (and in many cases only) treatment option for patients with end-stage organ failure. The effectiveness and functioning life of these transplants has improved each decade due to surgical and clinical advances, and accurate histocompatibility assessment. Patient exposure to alloantigen from another individual is a common occurrence and takes place through pregnancies, blood transfusions or previous transplantation. Such exposure to alloantigen's can lead to the formation of circulating alloreactive antibodies which can be deleterious to solid organ transplant outcome. The purpose of these guidelines is to update to the previous BSHI/BTS guidelines 2016 on the relevance, assessment, and management of alloantibodies within solid organ transplantation.

Solving the Conundrum of Eosinophils in Alloimmunity

Eosinophils are bone-marrow-derived granulocytes known for their ability to facilitate clearance of parasitic infections and their association with asthma and other inflammatory diseases. The purpose of this review is to discuss the currently available human observational and animal experimental data linking eosinophils to the immunologic response in solid organ transplantation. First, we present observational human studies that demonstrate a link between transplantation and eosinophils yet were unable to define the exact role of this cell population. Next, we describe published experimental models and demonstrate a defined mechanistic role of eosinophils in downregulating the alloimmune response to murine lung transplants. The overall summary of this data suggests that further studies are needed to define the role of eosinophils in multiple solid organ allografts and points to the possibility of manipulating this cell population to improve graft survival.

Venous Thromboembolic Complications in Pediatric Gastrointestinal Diseases: Inflammatory Bowel Disease and Intestinal Failure

In children with gastrointestinal disorders such as inflammatory bowel disease (IBD) and intestinal failure (IF), the risk of venous thromboembolism (VTE) is increased. VTE may lead to pulmonary embolism, sepsis and central line infection, stroke and post-thrombotic syndrome. The purpose of this review is to summarize current knowledge and recent advances around VTE management in pediatric gastroenterology with a focus on IBD and IF. The VTE incidence in children with IBD is reported to be around 4-30 per 10,000 patient-years, with higher incidences for hospitalized children. While in general, IF is less common than IBD, the VTE incidence in children with IF is around 750 per 10,000 patient-years. The most common risk factors for development of VTE involve deviations leading to Virchow's triad (endothelial damage, stasis, and hypercoagulability) and include active inflammation, particularly with colonic involvement, presence of a central venous catheter, underlying thrombophilia, reduced mobility, surgery, and hospitalization. Classes of anticoagulants used for treatment of VTE are low molecular weight heparins and vitamin K antagonists. However, the use of direct oral anticoagulants for treatment or prevention of VTE has not been studied in this pediatric population yet. Pediatric gastroenterologists apply different VTE prevention and treatment strategies due to lack of literature and lack of consensus. We discuss the role of primary and secondary prophylactic use of anticoagulants, and provide tools and recommendations for screening, prevention and management for the specific pediatric populations.

In vitro comparison of efficacy of catheter locks in the treatment of catheter related blood stream infection

BACKGROUND & AIMS

Venous access used for parenteral nutrition (PN) application is extremely important for patients with intestinal failure. Potential loss of venous access might be a catastrophy for the patient. Catheter infections are a serious complication of PN application. Systemic administration of antibiotics as well as local antibiotic locks into the catheter to sterilize the catheter are used to treat catheter infections. However, there is no clear recommendation applying use of antibiotic locks, that would specify the type and concentration of antimicrobial medication. Our objective were to compare the efficacy of different types of antimicrobial lock therapy (especially taurolidine) and their concentrations to eradicate infectious agents.

METHODS

Bacterial strains of microorganisms (Staphylococcus epidermidis, Staphylococcus aureus, methicillin resistant S. aureus (MRSA), Pseudomonas aeruginosa, multidrug-resistant P. aeruginosa, Candida albicans) were used. Subsequently, the catheter was exposed to the microbes and then was incubated with a specific lock for 2 or 24 h at 37 °C. We used these locks: ethanol 70%, taurolidine, gentamicine in concentrations 0,5, 1 and 10 mg/ml and vancomycine in concentrations 1, 5, and 10 mg/ml. The number of remaining CFU (colony forming units) was compared after incubation.

RESULTS

70% ethanol and taurolidine were most effective for all studied microorganisms. Gentamicine was more effective than vancomycine.

CONCLUSIONS

The most effective antimicrobial lock solutions to eradicate selected pathogenic agents were ethanol and taurolidine. Use of antibiotics is often effective after many hours of treatment and there is a risk of inadequate therapy.

Deciphering the Contribution of γδ T Cells to Outcomes in Transplantation

γδ T cells are a subpopulation of lymphocytes expressing heterodimeric T-cell receptors composed of γ and δ chains. They are morphologically and functionally heterogeneous, innate yet also adaptive in behavior, and exhibit diverse activities spanning immunosurveillance, immunomodulation, and direct cytotoxicity. The specific responses of γδ T cells to allografts are yet to be fully elucidated with evidence of both detrimental and tolerogenic roles in different settings. Here we present an overview of γδ T-cell literature, consider ways in which their functional heterogeneity contributes to the outcomes after transplantation, and reflect on methods to harness their beneficial properties.

Organ transplantation and gut microbiota: current reviews and future challenges

Organ transplantation is often the only effective treatment for patients with end-stage diseases, such as heart, liver, kidney and small bowel failure and is carried out frequently worldwide. Still the post-transplantation complications remain health- and life-threatening outcome that needed to be resolved. With the rapid development of molecular technologies in recent years, more and more researchers realize that the gut microbiota may play a critical role in human diseases. The intestinal microbiome has been proved to provide a lot of functions to the host, such as digesting food, modulating metabolism, promoting angiogenesis and regulating the immune system. Several studies have investigated the alteration of intestinal microbiota in post-transplantation patients and observed significant changes in the intestinal microbiome compared to the pre-transplant condition. Due to the abovementioned features that the gut microbiota may be used in the prognosis of clinical outcome of organ transplantation. In addition, the FMT (fecal microbiota transplantation), probiotics and prebiotics as the newest therapy methods, effectiveness of which has been verified in some diseases, such as Clostridium difficile infection, inflammatory bowel disease and other chronic disorders, might be used as the prognosis tool in organ transplantation as well. The purpose of this present review is to elucidate the relationship between gut microbiota and organ transplantation as well as the potential use of new therapies like fecal microbiota transplantation, probiotic and prebiotic administration after the transplantation, and provide some ideas for future researches in field of organ transplantation.

UK practice in the prevention of central venous catheter-associated thrombosis in adults on home parenteral nutrition

BACKGROUND

Maintaining central access is imperative for the delivery of home parenteral nutrition (HPN) in those with intestinal failure. Methods to reduce central venous catheter infection are well recognised; however, the prevention of line thrombosis is less well studied.

METHODS

This paper reviews the current evidence and reports a survey of current practice within the UK. Using an electronic survey, respondents were asked to detail their use of anticoagulation in different patient groups and the type of anticoagulation used.

RESULTS

41 replies were received from 31 centres. Only one responder used low-dose warfarin routinely; 80% however anticoagulated those with a previous line thrombosis and 65% anticoagulated those that had any deep vein thrombosis or pulmonary embolus. The most commonly used anticoagulant was dose-adjusted warfarin aiming for an international normalised ratio of 2-3.

CONCLUSIONS

The evidence from the current literature in both HPN and the wider field is that there is no clear evidence that anticoagulation is either beneficial or harmful in the prevention of line thrombosis. This survey suggested that practice is varied across the UK likely reflecting the lack of evidence within the current literature.

Plasma exchange in small intestinal transplantation between ABO-incompatible individuals: A case report

The aim of this study was to investigate the application of plasma exchange in small intestinal transplantation between ABO blood type-incompatible patients. A small intestinal transplantation case between ABO-incompatible individuals is hereby presented and analyzed. The main treatment included plasma exchange, splenectomy and immunosuppression. The patient undergoing small intestinal transplantation exhibited stable vital signs. A mild acute rejection reaction developed ~2 weeks after the surgery, which the patient successfully overcame. The subsequent colonoscopy and pathological examination revealed no signs of acute rejection. In conclusion, plasma exchange in combination with anti-immune rejection therapy proved to be an effective scheme for the management of small intestinal transplantation between ABO-incompatible patients.

Abnormal liver function tests in the parenteral nutrition fed patient

Liver dysfunction is common in individuals receiving parenteral nutrition (PN) and particularly in neonates and infants. Abnormalities of liver function tests in patients receiving short term PN are usually transient but in individuals receiving long term PN, substantial liver damage and ultimately end stage liver disease may occur. The aetiology is complex, involving a large number of patient related and nutrition related factors. The terminology intestinal failure associated liver disease (IFALD) is therefore more appropriate than PN associated liver disease. Effort should be made to prevent liver dysfunction by managing sepsis, avoiding parenteral overfeeding, employing cyclical parenteral feeding and encouraging enteral nutrition where possible. Intake of soybean based parenteral lipid emulsions should be reduced in individuals with established IFALD, possibly to be replaced by lipid emulsions containing medium chain triacylglycerol, monounsaturated fatty acids or fish oil although larger clinical studies are needed. Similarly, evidence supporting the widespread use of parenteral choline and taurine supplementation in the prevention or treatment of IFALD remains limited. There are more data to support the use of oral antibiotics to treat bacterial overgrowth and oral ursodeoxycholic acid in neonates. Ultimately, severe IFALD may necessitate referral for small intestine and/or liver transplantation.

Influence of immunosuppression on alloresponse, inflammation and contractile function of graft after intestinal transplantation

In small bowel transplantation (SBTx), graft manipulation, ischemia/reperfusion injury and acute rejection initiate a severe cellular and molecular inflammatory response in the muscularis propria leading to impaired motility of the graft. This study examined and compared the effect of tacrolimus and sirolimus on inflammation in graft muscularis. After allogeneic orthotopic SBTx, recipient rats were treated with tacrolimus or sirolimus. Tacrolimus and sirolimus attenuated neutrophilic, macrophage and T-cell infiltration in graft muscularis, which was associated with reduced apoptotic cell death. Nonspecific inflammatory mediators (IL-6, MCP-1) and T-cell activation markers (IL-2, IFN-gamma) were highly upregulated in allogeneic control graft muscularis 24 h and 7 days after SBTx, and tacrolimus and sirolimus significantly suppressed upregulation of these mediators. In vitro organ bath method demonstrated a severe decrease in graft smooth muscle contractility in allogeneic control (22% of normal control). Correlating with attenuated upregulation of iNOS, tacrolimus and sirolimus treatment significantly improved contractility (64% and 72%, respectively). Although sirolimus reduced cellular and molecular inflammatory response more efficiently after 24 h, contrary tacrolimus prevented acute rejection more efficiently. In conclusion, tacrolimus and sirolimus attenuate cellular and molecular inflammatory response in graft muscularis and subsequent dysmotility of the graft after allogeneic SBTx.

Long-term outcome of chronic intestinal pseudo-obstruction adult patients requiring home parenteral nutrition

OBJECTIVES

Chronic intestinal pseudo-obstruction (CIPO) is a rare, disabling disorder responsible for motility-related intestinal failure. Because it induces malnutrition, CIPO is a significant indication for home parenteral nutrition (HPN). The objective of the study was to evaluate long-term outcome of CIPO patients requiring HPN during adulthood.

METHODS

In total, 51 adult CIPO patients (18 men/33 women, median age at symptom occurrence 20 (0-74) years, 34/17 primary/secondary CIPO) followed up at our institution for HPN management between 1980 and 2006 were retrospectively studied for survival and HPN dependence rates using univariate and multivariate analysis.

RESULTS

Follow-up after diagnosis was 8.3 (0-29) years. Surgery was required in 84% of patients. The number of interventions was 3 +/- 3 per patient (mean +/- s.d.), leading to short bowel syndrome in 19 (37%) patients. Actuarial survival probability was 94, 78, 75, and 68% at 1, 5, 10, and 15 years, respectively. Multivariate analysis showed that lower mortality was associated with the ability to restore oral feeding at baseline (hazard ratio (HR) = 0.2 (0.06-0.65), P = 0.008) and symptom occurrence before the age of 20 years (HR=0.18 (0.04-0.88), P = 0.03). Higher mortality was associated with systemic sclerosis (HR=10.4 (1.6-67.9), P = 0.01). Actuarial HPN dependence was 94, 75, and 72% at 1, 2, and 5 years, respectively.

CONCLUSIONS

In this large cohort of CIPO adult patients with severe intestinal failure, i.e., those requiring HPN, we found a higher survival probability than previously reported. These results should be taken into account when considering intestinal transplantation.

Evaluation of c4d deposition and circulating antibody in small bowel transplantation

Antibody-mediated rejection (AMR) consensus criteria are defined in kidney and heart transplantation by histological changes, circulating donor-specific antibody (DSA), and C4d deposition in affected tissue. AMR consensus criteria are not yet identified in small bowel transplantation (SBTx). We investigated those three criteria in 12 children undergoing SBTx, including one retransplantation and four combined liver-SBTx (SBTx), with a follow-up of 12 days to 2 years. All biopsies (91) were evaluated with a standardized grading scheme for acute rejection (AR), vascular lesions and C4d expression. Sera were obtained at day 0 and during the follow-up. C4d was expressed in 37% of biopsies with or without AR, but in 50% of biopsies with severe vascular lesions. In addition, vascular lesions were always associated with AR and a poor outcome. All children with AR (grade 2 or 3) observed before the third month died or lost the graft. DSA were never found in any studied sera. We found no evidence that C4d deposition was of any clinical relevance to the outcome of SBTx. However, the grading of vascular lesions may constitute a useful marker to identify AR that is potentially resistant to standard treatment, and for which an alternative therapy should be considered.

Managing liver dysfunction in parenteral nutrition

Parenteral nutrition is life saving in patients with intestinal failure but liver dysfunction is commonly encountered, especially in neonates. Although abnormal liver function tests associated with short-term parenteral nutrition are usually benign and transient, liver dysfunction in both children and adults receiving long-term parenteral nutrition can progress to end-stage liver disease and liver failure. The aetiology of parenteral nutrition-associated liver disease is complex and multifactorial, with a range of patient, disease and nutrition-related factors implicated. Sepsis is of particular importance, as is the lack of enteral nutrition and overfeeding with intravenous glucose and/or lipid. Deficiencies of a number of amino acids including choline and taurine have also been implicated. Management of hepatic dysfunction in parenteral nutrition should initially focus on preventing its occurrence. Sepsis should be managed appropriately, enteral nutrition should be encouraged and maximised where possible and parenteral overfeeding should be avoided. Provision of parenteral lipid should be optimised to prevent the adverse effects of both deficiency and excess, and cyclical rather than continuous parenteral feeding should be administered. There is some evidence of benefit in neonates from oral antibiotics to prevent intestinal bacterial overgrowth and from oral ursodeoxycholic acid, but less to support their use in adults. Similarly, data to support widespread use of parenteral choline or taurine supplementation are lacking at present. Ultimately, severe parenteral nutrition-associated liver disease may necessitate referral for small intestine and/or liver transplantation.

Experimental small bowel preservation using Polysol: A new alternative to University of Wisconsin solution, Celsior and histidine-tryptophan-ketoglutarate solution?

AIM: To evaluate the potential of Polysol, a newly developed preservation solution, in cold storage of small bowel grafts, compared with the current standards, University of Wisconsin solution (UW), Celsior and histidine-tryptophan-ketoglutarate solution (HTK).

METHODS: Male Wistar rats were used as donors. Small bowels were retrieved, flushed and then stored in the respective 4 solutions for 18 h at 4°C. Functional integrity of the grafts was evaluated by isolated reperfusion with oxygenated Krebs-Henseleit buffer at 37°C for 30 min in all 4 groups.

RESULTS: Polysol preservation exhibited the highest tissue ATP concentration and the lowest release of LDH. Malondialdehyde, an index for tissue lipid peroxidation, was also the lowest in Polysol. Tissue oxygen consumption was significantly higher in Polysol than in the others. Of interest, UW-storage promoted 10-fold higher apoptosis than in the others. Moreover, electron microscopy revealed that the mucosal villi/micro-villi formation and the cell organelles, including mitochondria, were both significantly better preserved in Polysol, while deleterious alterations were apparent in the others, most notably in UW. Although Celsior and HTK exhibited the better trend of results than UW in some parameters, but could not reach the over-all superiority to UW.

CONCLUSION: Cold storage using Polysol resulted in significantly better integrity and function of small bowel grafts than UW. Hence, Polysol may be a novel alternative for the small bowel preservation.

Is intestinal transplantation now an alternative to home parenteral nutrition?

Patients with irreversible intestinal failure and complications of parenteral nutrition should now be routinely considered for small intestine transplantation. Despite attempts for >40 years immunological graft intolerance presented an impenetrable barrier to successful engraftment until the development in the late 1970s of the powerful calcineurin-inhibitor immunosuppressive agents. Their use over the last 17 years has led to small intestinal transplantation being generally considered as a routine option for patients with irreversible intestinal failure and failing parenteral nutrition. The 1-year patient survival rates (%) are now excellent for renal (95), liver (78), heart (82) and lung (75) transplantation. In contrast, survival rates for small intestinal transplantation have been slow to improve, although they are now approaching those for lung and liver transplantation (intestine 78%, intestine and liver 60%, multivisceral 66%), and well-performing centres report recent 1-year graft survival rates as high as 92%. Patient 5-year survival (%) has also improved (intestine alone 50, intestine and liver 50 and multivisceral 62) and compares increasingly favourably with renal (85), liver (67), heart (67) and lung (46). Currently, small intestinal transplantation is reserved for patients with irreversible small intestinal failure who have a poor prognosis on parenteral nutrition. However, as 5-year patient survival following intestinal transplantation approaches that for parenteral nutrition there will be increasing pressure to offer this modality of treatment as an alternative to parenteral nutrition, especially for those patients who have a poor quality of life as a result of parenteral nutrition.

Inhibition of Sonic Hedgehog Signaling Reduces Chronic Rejection and Prolongs Allograft Survival in a Rat Orthotopic Small Bowel Transplantation Model

BACKGROUND

Although acute graft rejection can be successfully controlled by immunosuppressive agents, chronic rejection (CR), which is characterized by arteriosclerosis in the donor organ vessels, is a major hurdle to long-term allograft survival. Sonic hedgehog (Shh), a morphogen critical in embryogenesis, also promotes peripheral immunity, which prompted us to investigate if inhibition of Shh signaling could reduce CR and thereby enhance allograft survival.

METHODS

In a rat orthotopic small bowel transplantation model, FK506 prevented acute rejection; however, recipients eventually lost their grafts by CR. Anti-Shh antibody or isotype control were administered to animals at day 30 postoperatively. Graft survival, tissue fibrosis, vascular occlusion, and expression of vascular endothelial growth factor (VEGF) were investigated.

RESULTS

Immunostaining revealed that Shh and the Hedgehog receptor Patched 1 (Ptc1) are strongly expressed in CR grafts and that Ptc1 expression partially overlapped with that of ED-1, a macrophage marker. In contrast, only minimal expression of Shh and Ptc1 was detected in syngeneic grafts. Grafts survival was significantly prolonged after anti-Shh antibody treatment compared with the immunoglobulin G control (116 vs. 77.5 days). Collagen deposition and vascular occlusion in the mesentery were markedly reduced in recipients of the anti-Shh antibody. Specific transcripts and protein expression for VEGF, which was present mainly in the blood vessels, were reduced.

CONCLUSION

In a rat small bowel transplantation model, anti-Shh antibody treatment reduced CR and prolonged graft survival. These beneficial effects of Shh treatment may occur partly by reducing VEGF expression in the blood vessels of the allografts.

Short bowel syndrome: parenteral nutrition versus intestinal transplantation. Where are we today?

Current management of short bowel syndrome (SBS) revolves around the use of home TPN (HPN). Complications include liver disease, catheter-related infections or occlusions, venous thrombosis, and bone disease. Patient survival with SBS on TPN is 86% and 75% at 2 and 5 years, respectively. Surgical management of SBS includes nontransplant surgeries such as serial transverse enteroplasty and reanastomosis. Small bowel transplant has become increasingly popular for management of SBS and is usually indicated when TPN cannot be continued. Posttransplant complications include graft-versus-host reaction, infections in an immunocompromised patient, vascular and biliary diseases, and recurrence of the original disease. Following intestinal-only transplants, patient and graft survival rate is 77% and 66% after 1 year. After 5 years the survival figures are 49% and 34%, respectively. Future improvements in survival and quality of life will enhance small bowel transplant as a viable treatment option for patients with SBS.

Sustainability of mechanically lengthened bowel in rats

INTRODUCTION

It has been shown that the length of an intestinal segment may be doubled by applying gradual mechanical stretching. This study evaluated whether the lengthened intestinal segment retained the structure and function after the stretching device was removed.

METHODS

A 1.5-cm jejunal segment was separated from intestinal continuity in 20 rats. After advancing a screw into the isolated jejunal segment by 5 mm 3 times a week until it was stretched by 3 cm, the screw was removed. Three weeks later, the jejunal segments were retrieved for analyses. Comparisons were made between the lengthened jejunal segments.

RESULTS

The jejunal segment doubled its length after gradual stretching and retained this length 3 weeks after the screw removal (3.1 +/- 0.8 vs 3.2 +/- 0.4 cm, P > .05). The villous height, the muscular thickness, and the total alkaline phosphatase and lactase activities of the stretched jejunal segments were also unchanged 3 weeks after the screw removal.

CONCLUSIONS

Mechanical force induced the sustained lengthening of isolated jejunal segments in rats. The histologic and enzymatic alterations also persisted 3 weeks after the mechanical force was removed. This phenomenon may provide a novel method for the treatment of short bowel syndrome.

Survival and dependence on home parenteral nutrition: experience over a 25-year period in a UK referral centre

BACKGROUND

Home parenteral nutrition (HPN) is the standard treatment for severe intestinal failure in the United Kingdom.

AIM

To review long-term survival and ongoing HPN dependence of patients receiving HPN treated at a specialist UK referral centre.

METHODS

Medical records of patients commenced on HPN between 1979 and 2003 were reviewed retrospectively. Regression analysis was employed to identify factors associated with poor prognosis.

RESULTS

Case notes of 188 patients were reviewed. Overall probability of survival was 86%, 77%, 73% and 71% at 1, 3, 5 and 10 years after starting treatment. In multivariate analysis, association was seen between mechanism of intestinal failure and survival: short bowel syndrome associated with a favourable prognosis, and intestinal dysfunction, dysmotility and obstruction with poorer prognoses. There was an association between increasing age and poor prognosis, but increased mortality was also seen in the youngest age groups. Only 9% of deaths were due to complications of HPN. Continued HPN dependence was 89%, 87%, 84% and 84% at 1, 3, 5 and 10 years in survivors.

CONCLUSIONS

Long-term survival of patients receiving HPN remains better than that reported after intestinal transplantation. Mortality predominantly relates to underlying disease rather than complications of HPN.