Abstract Background Treatment of Crohn’s disease (CD) involves medications and surgery but experiencing medication side effects (SE) limits medical options. The aim of this study was to compare SE experienced by patients with CD and intestinal failure (CD-IF) vs. CD without IF as this may contribute to a higher surgical requirement. Methods A single tertiary centre retrospective analysis was performed on CD-IF patients on parenteral nutrition due to short-bowel syndrome vs. small bowel CD without IF. Patients with CD without IF were selected from consecutive clinics who lived in the local catchment area. Results 94 CD-IF and 94 CD patients were included. The proportion of female patients was 56.4% (CD-IF) and 46.8% (CD); mean age was 51.2 (CD-IF) and 41.5 years (CD); mean duration of disease 24 years (CD-IF) and 16 years (CD). Most CD-IF patients had multiple resections. In the CD group, 50 patients never had surgery, 22 had 1 resection, and 9 had 2 or more. From the past medication history for these patients, the proportion in whom a medication was stopped due to SE was similar for CD-IF and CD for azathioprine, mercaptopurine and vedolizumab (Table 1). There were no SE to ustekinumab. Patients in the CD-IF group had a preceding history of significantly more SE to anti-TNF therapy and methotrexate were observed in CD-IF group, of which allergies were most frequent. In the CD group, 2 patients previously had an allergic reaction to infliximab whereas, in the CD-IF group 6 patients had a history of anaphylaxis and 5 an allergy to infliximab, 1 had an allergy to adalimumab and 3 to methotrexate (Table 2). Data on drug levels amongst those with allergy events were limited (due to prior availability of testing); of those tested, 1 had positive antibodies and 1 did not. The frequency of non-response and loss of response was similar between the two groups for each medication. Conclusion The frequency of SE to immunomodulators and biologics was similar between CD and CD-IF, except for anti-TNF therapy and methotrexate due to more allergy/anaphylaxis events in CD-IF. The frequency of these reactions may have caused an earlier shift towards surgical treatment. 92/94 CD-IF patients were diagnosed prior to 2014; it would be useful to review the incidence of CD-IF before 2014 (pre-vedolizumab and ustekinumab) vs. the new biological era.

Abstract Background Intestinal failure (IF) is an uncommon complication of severe Crohn’s disease (CD) due to extensive or recurrent resections or complications. It is observed that disease activity might remit once IF develops. This is unexpected given the previous disease course. The aim of this study is to compare the number of patients in deep remission with CD–intestinal failure (CD-IF) to CD without IF. Methods A single tertiary centre retrospective analysis was performed on CD-IF patients on parenteral nutrition due to short bowel vs. patients with small bowel CD. CD patients were selected from consecutive hospital clinics if they lived in the local catchment area. Deep remission was defined by the lack of objective indicators of inflammation during the year prior to their latest clinic; including imaging, endoscopy and faecal calprotectin. Results 94 CD-IF and 94 CD patients were included. The proportion of female patients was 56.4% (CD-IF) and 46.8% (CD); mean age was 51.2 (CD-IF) and 41.5 years (CD); mean duration of disease 24 (CD-IF) and 16 years (CD); proportion with a stoma 73.4% (CD-IF) and 7.4% (CD). In the CD-IF group, 80.9% were in deep remission compared with 37.2% in the CD group (p < 0.0001) (Table 1). Medication requirements were higher in the CD group. 45/94 (47.9%) (CD-IF) vs. 27/94 (28.7%) (CD) (p = 0.005) were not on medications Biologics were required by 23/94 (24.5%) (CD-IF) vs. 48/94 (51.1%) (CD) (p = 0.0003). Combination therapy (immunomodulator and a biologic) was required by 6/94 (6.4%) (CD-IF) vs. 26/94 (27.7%) (CD) (p = 0.0003) (Table 2). 17 of the 27 CD patients not on medications were in remission and 10 had active disease (of whom 2 refused treatment, 1 was pregnant and 7 had stable mild disease with no major symptoms). 38 of the 45 CD-IF patients off medications were in remission and 7 had active disease (of whom 2 had surgery, 2 are due to start biologics, 1 died and 2 had stable mild disease). Conclusion CD-IF patients were more often in remission than those with CD; they required less medications and less biologics. Plausible reasons for this observation could include that there is less bowel which can inflame; perhaps parenteral nutrition or an altered diet has a protective effect via modulation of the microbiota.

BackgroundThe purpose of this study was to determine factors which may be associated with poor wound healing in patients with perianal Crohn's disease (pCD) who had undergone proctectomy in the biologics era.

Intravenous (IV) steroids remain the standard first-line treatment for patients admitted with acute ulcerative colitis (UC). However, 30% of patients fail to respond and require second-line therapies and/or surgery. The purpose of this study was to determine whether Day 1 parameters could identify a group at high risk of failing first-line therapies. All admissions for acute UC (ICD-10 K51) to hospitals in NHS Lothian (4 sites) and St Mark’s Hospital, Harrow from 1/11/11 to 31/10/16 were obtained from the regional coding departments. Case record review was performed. Response to IV steroids was defined as discharge from hospital with no further acute medical or surgical treatment. Non-response was defined as need to escalate to ciclosporin, infliximab, other acute therapy, or to have surgery. The following parameters were recorded for the first 10 days post admission: haemoglobin (Hb), platelet count, CRP, albumin, stool frequency and faecal calprotectin. Each patient was later attributed a score based on CRP (≤50 mg/dl = 0; >50 mg/dl = 1), albumin (≥30 g/l = 0; < 30 g/l = 1) and platelets (≤400 × 109/l = 0; >400 × 109/l = 1). In total, 592 admissions with acute UC were identified; 391/592 (66%) responded to steroids, 201/592 (34%) patients were non-responders. 44 (22%) non-responders received infliximab as second-line therapy, 108 (54%) cyclosporine, and 4 (2%) other. Eighty-three (41%) non-responders required surgery; 7 (8%) had infliximab prior to surgery; 35 (42%) cyclosporine; 12 (14%) went straight to surgery. Insufficient data were available regarding 33 patients. On univariate analysis, albumin (p = <0.001), platelet count (p = 0.004) and CRP (p = <0.001) were significantly different between responders and non-responders. On multi-variate analysis platelets were not significant. No difference was seen for Hb or stool frequency. 64.3% of patients with concurrent hypoalbuminaemia, high CRP and high platelets (score = 3) were non-responders. Table 1. Day one results. Table 2. Patient scoring. A third of patients failed to respond to IV steroids. Day of admission albumin, CRP and platelets significantly predicted failure of first-line therapy. 64.3% of patients with a score of 3 failed first-line medical therapy. The combination of these readily available parameters identifies a high-risk population who may benefit from earlier second-line medical or surgical intervention.

Background: Anti-TNF treatments have improved the outcomes for patients with inflammatory bowel disease (IBD). However, they are associated with an increase in risk of Tuberculosis (TB). The aim of this study is to determine the proportion of latent TB infections (LTBI) in our IBD cohort treated with anti-TNFs and the management of these patients. We also examined the effect of different immunosuppressive drugs on the indeterminate rate of the interferon-gamma release assays (IGRA) in LTBI screening Methods: We conducted a retrospective review of all patients treated with biologics between March 2007 and November 2015. Patient notes and electronic records were reviewed. LTBI screening was assessed using a risk assessment form, chest x-ray, and tuberculin skin test (TST) or IGRA for the screening for LTBI and the nature of the immunosuppressive treatment was documented. Results: 732 patients with IBD were screened for LTBI before starting a biological treatment during the study period. 31 of 732 (4%) IBD patients were diagnosed and treated for LTBI with no significant side effects. 596 of 732 received their biologic treatment with a median delay of 86 days in initiating biologics. 6 of 596 patients who received biologic treatment developed active TB; 5 of whom were Caucasian. 247 patients were screened with an IGRA test. 6 were positive, 162 were negative and 79 patients were indeterminate. 45% with indeterminate IGRA had a repeat; half were negative and half remained indeterminate. 73% of the patients were receiving immunosuppressive (IMM) medication(s). There was a higher indeterminate rate of the IGRA in the IMM group compared to the no-IMM group (32% compared to 9%). The combination of steroids and thiopurines gave the highest rate of an indeterminate IGRA. High and low doses of steroids were equally likely to result in an indeterminate IGRA result. Conclusions: 4% of patients screened had LTBI and 1% of patients treated with biologics developed active TB. Delays in initiating biologics due to LTBI screening may have detrimental effects on the IBD management. Almost one third of patients on immunosuppressants had an indeterminate IGRA, which supports the need for a guideline incorporating a risk stratification strategy based on factors such as country of birth and local TB prevalence. There is a need to remain vigilant for TB regardless of baseline LTBI results or epidemiological factors.

Introduction Anti-TNF therapies for inflammatory bowel disease (IBD) can lead to a five fold increase of tuberculosis (TB) reactivation in patients with latent TB infection (LTBI). Current European Crohn’s and Colits Organisation recommends LTBI screening with Interferon Gamma Release Assay (IGRA) according to local prevalence, national recommendations and preferred in BCG immunised individuals. In this study, we determine the proportion of LTBI in our cohort of IBD patients treated with biologics and any complications of treatment, particularly drug-induced liver injury (DILI). Methods All patients with IBD who were treated with biologics between March 2007 and November 2015 were identified from the high cost funding database held at the Pharmacy of St Mark’s Hospital. Case notes and electronic records were retrospectively reviewed to identify records of LTBI screening. The following were excluded from the analysis: those who were treated for active TB and those who did not receive treatment either for latent or active TB. Of note, at this site, in July 2013, an IGRA testing replaced the Mantoux on our screening algorithm. DILI was defined as deranged liver function tests with no other identifiable cause. Results Seven hundred and thirty-two IBD patients were screened for TB prior to starting a biologic. 31 patients (4.2%) were identified as having LTBI and had prophylactic treatment for TB (19 with single agent isoniazid; 12 dual agent isoniazid and rifampicin). Of these 31 patients, 22 went on to have anti-TNF treatment with a median delay of 86 days (range = 7–336 days). Of the 31 that went on to have treatment for latent TB, 3% (n = 1) had side effects, dizziness which was not severe to be stopped the LTBI treatment and non had DILI. Conclusion Rate of LTBI in this population receiving biologics for IBD was 4%; all identified patients were treated and none experienced significant side effects. The median time to starting biologics after screening was 86 days, which may represent a significant delay in starting biologics for the IBD patients; this could have detrimental effects to their IBD related morbidity. There remains the risk of false negative IGRA results in an immunosupressed patient and, as such, place of birth and likely previous exposure should be taken into account. Reference 1 Rahier J, Moutschen M, Van Gompel A, Van Ranst M, Louis E, Segaert S, et al. Vaccinations in patients with immune-mediated inflammatory diseases. Rheumatology (Oxford) 2010;49:1815–1827. Disclosure of Interest None Declared

Introduction Biologic treatment has improved outcomes of patients with complex inflammatory bowel disease (IBD). Anti-TNF therapy is associated with a fivefold increased risk of reactivation of tuberculosis (TB). When TB occurs, it is commonly extra-pulmonary and disseminated with an atypical presentation and can be diagnostically challenging. An indeterminate interferon gamma release assay (IGRA) result occurs in <2% of the healthy population, however this is higher in immunosuppressed patients. Given the increased risk of TB, screening for latent TB infection (LTBI) remains vital before commencing biologics. Methods All IBD patients who had an IGRA test between July 2013 and November 2015 before commencing biologic therapy were identified from the high cost funding database held in the Pharmacy Department at St Mark’s Hospital. Clinical and electronic case records were reviewed. Results 247 patients were screened for TB with an IGRA test during the study period. The mean age was 36.9 years (range 8–85), 54% were male and 70% had Crohn’s disease. 78 patients (32%) had an indeterminate IGRA result and 35/78 (45%) patients had a repeat test; 17/35 (49%) had a second indeterminate results and the remaining 18 /35 (51%) had a negative test. 8/78 with an indeterminate test had a Mantoux as per our algorithm; 3 were positive, 4 were anergic and 1 was negative. Of the 247 patients, 210 patients received biologic treatment. Thirty-two patients (15%) delayed receiving their biologic treatment for various reasons, including receiving LTBI treatment. Of 210 patients, 158 patients (75%) had Infliximab,38 patients (18%) had Adalimumab, 13 had Vedolizumab and 1 had Golimumab. 30 patients were referred for an infectious diseases opinion; 7 with a positive IGRA and 7 with a negative IGRA but abnormalities on their chest X-ray and a high epidemiological risk for TB. One patient who had an indeterminate IGRA result developed active TB during the study period. Conclusion Almost one third of IBD patients had an indeterminate IGRA with half of those having a second indeterminate result. Sampling and processing factors also influence the prevalence of indeterminate results in this population. This supports risk stratification with more weight added to the risk than IGRA alone. Reactivation of LTBI may lead to delays in starting treatment hence it is vital to take into account the patient’s pre-test probability of LTBI before using an IGRA to avoid such delays. Reference 1 Wong H, Ip M, Tang W, et al. Performance of the interferon-gamma release assay for Tuberculosis screening in inflammatory Bowel disease patients. IBD 2014;20(11):2067–2072. Disclosure of Interest None Declared

Introduction Anti-tumour necrosis factor agents (anti–TNF) are major advances in the management of inflammatory bowel disease (IBD) however they are associated with a 5 fold increased risk of Mycobacterium tuberculosis (TB) infection. All patients should be screened for latent TB infection (LTBI) prior to anti-TNF therapy. Here, we review active TB cases after anti-TNF therapy to identify lessons to be learned. Methods All patients with IBD treated with anti-TNF between March 2007-November 2015 were identified from pharmacy database. Those who developed active TB were identified from the London TB register. Clinical and electronic notes were reviewed. LTBI screening is with history, Chest X-Ray (CXR) and tuberculin skin test (TST) before July 2013 or Quantiferon Gold Assay (QFT-G) after July 2013. Results Of 596 patients treated with anti-TNF, 6 had active TB. 5 had Crohn’s and 1 had Ulcerative Colitis. 3 were male, none had HIV. Age range was 24–49 years. 5 were Caucasian, 1 was UK born but of Pakistani origin. 3 were on Adalimumab (ADA) at time of TB diagnosis and 2 on Infliximab (IFX), 3 were on at least 1 other immunosuppressive. 1 was not on anti-TNFs at TB diagnosis but received IFX 3 months earlier. Time from initiation of anti-TNF to TB diagnosis ranged from 3–41 months (median:13, IQR = 32). 3 had culture confirmed TB, 1 was MTB complex PCR positive but culture negative and 2 had presumed TB. All isolated cultures were fully sensitive. 2 had miliary TB, 2 abdominal TB, 1 pleuro-pulmonary TB and 1 both pulmonary and pericardial TB. Treatment duration was 6–12 months, 5 patients completed treatment and 1 remains on treatment. 3 had prior vaccination for TB, 1 did not and the vaccination status of 2 was unknown. 4 patients had negative TSTs pre-anti-TNF (3 while immunosuppressed), 1 had an indeterminate QFT-G test (while immunosuppressed) and 1 had neither. All patients had normal CXR prior to anti-TNF. No patients received LTBI treatment. Conclusion All cases were considered low epidemiological risk for LTBI . None had a positive TST or QFT-G, however the risk of false negatives is high in immunosuppression. As some patients screened may receive prolonged and recurrent courses of anti-TNF, we recommend discussion around when patients should be rescreened. It is unclear if these cases represent de novo infection or reactivation of latent disease but re-screening may have identified them at the latent stage. As it is not possible to prevent all cases of active TB, there must be continued focus on prompt diagnosis and treatment, alongside comprehensive screening by working with local TB services. Disclosure of Interest None Declared

Introduction Sphincterotomy and balloon/basket trawl at ERCP is the standard treatment to clear stones from the common bile duct. The BSG in 2014 published a key performance indicator of >75% stone clearance during first ERCP. Balloon sphincteroplasty as an adjunct to sphincterotomy can increase stone clearance. The aim of this study is to review the success/safety for balloon sphincteroplasty compared to sphincterotomy alone. Methods Retrospective study between 1st April 2010–2014 in a large district general hospital of all ERCPs documenting a common bile duct stone. Electronic records were analysed with the following exclusion criteria: anticoagulants, biliary leak, unchecked cardiac device or incomplete follow up. Balloon sphincteroplasty was always performed after a sphincterotomy, using a Boston Scientific CRE wire guided balloon with a maximal diameter dilation that corresponded to the patient’s mid common bile duct diameter (8–15 mm). Results Total study population was 390 patients. Stone clearance with initial sphincterotomy alone and balloon/basket trawl was successful in 70% (n = 274) patients. 116 patients underwent additional balloon sphincteroplasty with a success rate of 85.5% (n = 100). The remaining patients underwent mechanical lithotripsy (n = 15) or tertiary care referral (n = 1). Therefore, sphincterotomy +/- balloon sphincteroplasty achieved stone clearance in 96% (n = 374) of patients. No statistically significant diferences were observed for complication rates when comparing sphincterotomy alone to balloon sphincteroplasty. Actual complication rates for sphincterotomy alone/balloon sphincteroplasty were: overall 5%/5.2%; pancreatitis 1%/2.6%; cholangitis 3%/3%; bleeding 3%/0% perforation 0%/0%. Conclusion Balloon sphincteroplasty is an effective and safe adjunct in patients who do not achieve bile duct stone clearance with sphincterotomy and balloon/basket trawl alone, allowing clearance rates to exceed current guideline recommendations. Reference 1 Wilkinson, et al. BSG ERCP – the way forward, A standards framework. 2014. http://www.bsg.org.uk Disclosure of Interest None Declared

Introduction Indeterminate interferon-gamma release assay (IGRA) results when screening for latent tuberculosis infection (LTBI)prior to biologic use in inflammatory bowel disease (IBD) may delay biologic treatment initiation. Concomitant steroids affect IGRA result, however the impact of other immunosuppressive medications is less clear. We determine the effect of immunosuppressives on results of IGRAs. Methods All patients treated with biologics from July 2013-November 2015 were identified from a pharmacy database. Electronic and clinical records were reviewed for IGRA result and concomitant immunosuppressive use. X2 was used to compare categorical data and univariate logistic regression using SPSS was used to determine likelihood of indeterminate tests with different immunomodulator medications (IMM). Results 247 patients with IBD had an IGRA. Mean age: 36.9 years (range 8–85) and 54% were male. 78/247 (32%) had an indeterminate result and 35/78 (45%) patients had a repeat test; 17/35 (49%) had a second indeterminate result. 181/247 (73%) received at least one IMM prior to screening and 66 patients (27%) were not on any IMM (IMM-free). In the IMM group: 121/181 (67%) patients had thiopurines, 18/181 (10%) had corticosteroids, 25/181 (14%) had both, 9/181 (5%) had methotrexate and 7/181 (4%) had other IMMs at screening. 72/181 (40%) had a first indeterminate IGRA 59/181 (33%) had a second indeterminate result. In the IMM-free group: 6/66 (9.0%) had an indeterminate IGRA. Patients in IMM group were more likely to have an indeterminate results than patients in IMM-free group (33% v 9.0%, p = 0.00001). Each separate IMM group was more likely to be associated with an indeterminate IGRA result compared with those in IMM-free group: thiopurines (23%) p = 0.020, steroids (42%) p = 0.001, thiopurines and steroids (64%) p = 0.001, other (43%) p = 0.01 and methotrexate (44%) p = 0.008). The combination of steroids and thiopurines together was the strongest factor associated with an indeterminate result. High dose (Prednisolone >20 mg or intravenous Hydrocortisone) and low dose steroids (Prednisolone <20 mg or Budesonide) were equally likely to cause an indeterminate result (66.6% v 50.0%, p = 0.68). Conclusion A combination of thiopurines and steroids gave the highest likelihood of an indeterminate IGRA result, although significant results occurred with all IMMs. This has implications for LTBI screening in IBD patients. Guidelines to address indeterminate IGRA results, perhaps with more focus on epidemiological risk may be helpful. There is an unmet need to have improved assessment tools for TB in patients on IMMs. Disclosure of Interest None Declared

Introduction Abnormal liver function tests (LFTs) are present in up to 40% of patients with Inflammatory Bowel Disease (IBD). These abnormalities are often transient. A few studies in the current literature suggest that transient disturbances may be related to disease activity,1,2whilst others have failed to find a causal association.3The aim of this study is to identify the link between abnormal LFTs and IBD activity. Method Literature review was performed using Pubmed. For the retrospective study, patients with Ulcerative Colitis (UC) and Crohn’s disease (CD) who were admitted to our institution in 2013 were identified. Patient’s electronic records were used. Exclusion criteria: less than 16 years old, LFTs documented for less than 12 months or on less than 3 occasions. Abnormalites were defined as ’transient’ if at least one of: alanine transaminase, alkaline phosphatase or bilirubin was disturbed for less than 4 weeks or ‘persistent’ if disturbed for more than 4 weeks. Results 8 studies were included in the literature review. There was significant heterogeneity in the frequency of abnormal LFT (3%4to 40%2) due to variations in the definitions used. Our study included 264 CD patients and 310 UC patients who were followed for a median of 34 months. Abnormal LFTs were found in 242/574 (42%) patients. 66% of abnormalities were transient and 34% were persistent. The causes identified for 192 patients with transient abnormalities were: 70 IBD flare, 52 antibiotics/infection, 3 thiopurine drugs, 59 unknown, 3 fatty liver, 5 other. The causes identified for 99 patients with persistent abnormalities were: 22 IBD flare, 14 infections, 12 PSC, 18 unknown cause, 5 fatty liver, 4 Gilberts, 5 thiopurine drugs, 3 pregnant, 16 other. Conclusion This study lends support to the notion that an IBD flare can cause deranged LFTs independently of thiopurine drugs. Mild abnormalities during a flare can be monitored. Further investigations are warranted if the bilirubin is raised or if the LFTs are markedly deranged or persist more than 4 weeks after resolution of the flare. Disclosure of interest None Declared. References Broome U, Glaumann H, Hellers G, Nilsson B, Sorstad J, Hultcrantz R. Liver disease in ulcerative colitis: an epidemiological and follow up study in the country of Stockholm. Gut. 1994;35(1):84–89 Yamamoto-Furusho JK, Sanchez-Osorio M, Uribe M. Prevalence and factors associated with the presence of abnormal liver function tests in patients with ulcerative colitis. Ann Hepatol. 2010;9(4):397–401 Mendes FD, Levy C, Enders FB, Loftus EV, Angulo P, Lindor KD. Abnormal hepatic biochemistries in patients with inflammatory bowel disease. Am J Gastroenterol. 2007;102:344–350 Shepherd HA, Selby WS, Chapman RW, Nolan D, Barbatis C, McGee JO, Jewell DP. Ulcerative colitis and persistent liver dysfunction. Q J Med.1983;52(208):503–13

Introduction Parenteral nutrition (PN) via a central venous catheter (CVC) is associated with risk of thrombosis and catheter-related bloodstream infection (CRBSI). Factors believed to reduce the risk of infection include using a tunnelled CVC or peripherally inserted central catheter (PICC), and using a single lumen CVC where possible. A CVC tip above the mid-section of the superior vena cava increases thrombosis risk.1 Strict aseptic technique is required to prevent CRBSI. Methods Between 1st January and 31st December 2011 patients transferred to the St Mark's Intestinal Failure Unit with a CVC in situ for PN were assessed. We recorded CVC type, number of lumens, and CVC tip position (see [Abstract OC-035 figure 1][1]: dashed lines (mid & proximal superior vena cava (SVC), brachiocephalic, subclavian & internal jugular veins) & solid lines (distal third SCV, proximal & distal right atrium). CVC tip position in the dashed region is associated with a higher thrombosis risk (Cadman et al ).1 Blood cultures were taken from all lumens of the CVC. CVCs with bacteraemia were treated with antibiotics. If a CVC was felt to be unusable it was removed. Reasons included tip position, multiple lumens, unsuitable for long-term use (not PICC or tunnelled), or for use by patient (PICC), CVC-related sepsis, CRBSI at risk of seeding ( S aureus or fungus), and >1 CVC in situ. ![Abstract OC-035 Figure 1][2] Abstract OC-035 Figure 1 Results 60 patients with 65s CVC from other centres were transferred. Some patients were admitted more than once. 24 were female and 36 were male, from 41 English Hospitals & two from Kuwait. 21 CVCs were tunnelled, 22 untunnelled, 21 were PICCs and one was a midline. Results are summarised in [Abstract OC-035 table 1][3]. 32(48%) CVCs had a tip that was too high, increasing thrombosis risk. 32% (21/65) of blood cultures were positive. 12 (18%) CVCs were retained and used. 13 (20%) were removed because of discontinuation of PN. 38 (58%) of CVCs were replaced. View this table: Abstract OC-035 Table 1 Results Conclusion This data demonstrates that on transfer patients CVCs are often infected, have a tip that is too high and multi-lumen CVCs are placed inappropriately. Reasons may include lack of attention to aseptic technique, lack of awareness of the thrombosis risk from a high CVC tip, and lack of availability of single lumen tunnelled CVCs as stock. Competing interests None declared. Reference 1. Cadman A , Lawrance JAL, Fitzsimmons L, et al. To clot or not to clot? That is the question in central venous catheters. Clin Radiol 2004; 59 :349–55. [1]: #F1 [2]: pending:yes [3]: #T1