Alexander R. Robertson

Alexander R. Robertson

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Previous Organizations / Institutes

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Alexander R. Robertson has a total of 77 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Abstract 2234: CD46 is a protein receptor for Human Adenovirus Type 64

    by Alexander Robertson, Eugene Wu, Emily Romanoff, Jesse Woon, Corina Stasiak

  • Open Access

    Nomenclature and Definition of Atrophic Lesions in Small Bowel Capsule Endoscopy: A Delphi Consensus Statement of the International CApsule endoscopy REsearch (I-CARE) Group

    by Luca Elli, Beatrice Marinoni, Reena Sidhu, Christian Bojarski, Federica Branchi, Gian Eugenio Tontini, Stefania Chetcuti Zammit, Sherine Khater, Rami Eliakim, Emanuele Rondonotti, et al.

    (1) Background: Villous atrophy is an indication for small bowel capsule endoscopy (SBCE). However, SBCE findings are not described uniformly and atrophic features are sometimes not recognized; (2) Methods: The Delphi technique was employed to reach agreement among a panel of SBCE experts. The nomenclature and definitions of SBCE lesions suggesting the presence of atrophy were decided in a core group of 10 experts. Four images of each lesion were chosen from a large SBCE database and agreement on the correspondence between the picture and the definition was evaluated using the Delphi method in a broadened group of 36 experts. All images corresponded to histologically proven mucosal atrophy; (3) Results: Four types of atrophic lesions were identified: mosaicism, scalloping, folds reduction, and granular mucosa. The core group succeeded in reaching agreement on the nomenclature and the descriptions of these items. Consensus in matching the agreed definitions for the proposed set of images was met for mosaicism (88.9% in the first round), scalloping (97.2% in the first round), and folds reduction (94.4% in the first round), but granular mucosa failed to achieve consensus (75.0% in the third round); (4) Conclusions: Consensus among SBCE experts on atrophic lesions was met for the first time. Mosaicism, scalloping, and folds reduction are the most reliable signs, while the description of granular mucosa remains uncertain.


  • Open Access

    An Overview of Robotic Capsules for Drug Delivery to the Gastrointestinal Tract

    by Pablo Cortegoso Valdivia, Alexander R. Robertson, Nanne K. H. De Boer, Wojciech Marlicz, Anastasios Koulaouzidis

    The introduction of capsule endoscopy two decades ago marked the beginning of the “small bowel revolution”. Since then, the rapid evolution of microtechnology has allowed the development of drug delivery systems (DDS) designed to address some of the needs that are not met by standard drug delivery. To overcome the complex anatomy and physiology of the gastrointestinal (GI) tract, several DDS have been developed, including many prototypes being designed, built and eventually produced with ingenious drug-release mechanisms and anchoring systems allowing targeted therapy. This review highlights the currently available systems for drug delivery in the GI tract and discusses the needs, limitations, and future considerations of these technologies.


  • Open Access

    Thrombin Is an Effective and Safe Therapy in the Management of Bleeding Gastric Varices. A Real-World Experience

    by Sarah-Louise Gillespie, Norma C. McAvoy, Diana E. Yung, Alexander Robertson, John N. Plevris, Peter C. Hayes

    Variceal haemorrhage is a severe complication of liver disease with high mortality. Human recombinant thrombin has gained popularity in the management of variceal haemorrhage. We report on the use of thrombin for gastric and ectopic varices at a regional tertiary care centre. This was a retrospective observational study. Patients with portal hypertension who received endoscopic injection of recombinant thrombin were identified and data collected on haemostasis and rebleeding rates, complications and mortality. Patients were grouped by indication for thrombin injection: gastric/oesophageal/ectopic varices and endoscopic band ligation (EBL)-induced ulceration. 155 patients (96M/59F, mean age 58.3 years) received endoscopic thrombin injection. Mean volume of thrombin injected at index endoscopy was 9.5 ml/2375IU. Initial haemostasis was achieved in 144 patients (92.9%). Rebleeding occurred in a total of 53 patients (36.8%) divided as follows: early rebleeding ( 30 days)—11 patients (7.6%). There was statistically significant difference in rate of initial haemostasis between Child-Pugh A/B patients vs Child-Pugh C (p = 0.046). There was no significant difference in rebleeding rates between different indication groups (p = 0.78), by presence of cirrhosis or by Child-Pugh Score. All-cause mortality at 6 weeks was 18.7%; 1-year mortality 37.4% (median follow-up 48 months). There was no significant difference in mortality between groups (p = 0.37). No significant adverse events or complications were reported. Thrombin is effective and safe for gastric varices and other portal-hypertension-related bleeding including oesophageal varices, ulcers secondary to EBL and ectopic varices.


  • Open Access

    Frontiers of Robotic Gastroscopy: A Comprehensive Review of Robotic Gastroscopes and Technologies

    by Wojciech Marlicz, Xuyang Ren, Alexander Robertson, Karolina Skonieczna-Żydecka, Igor Łoniewski, Paolo Dario, Shuxin Wang, John N Plevris, Anastasios Koulaouzidis, Gastone Ciuti

    Upper gastrointestinal (UGI) tract pathology is common worldwide. With recent advancements in robotics, innovative diagnostic and treatment devices have been developed and several translational attempts made. This review paper aims to provide a highly pictorial critical review of robotic gastroscopes, so that clinicians and researchers can obtain a swift and comprehensive overview of key technologies and challenges. Therefore, the paper presents robotic gastroscopes, either commercial or at a progressed technology readiness level. Among them, we show tethered and wireless gastroscopes, as well as devices aimed for UGI surgery. The technological features of these instruments, as well as their clinical adoption and performance, are described and compared. Although the existing endoscopic devices have thus far provided substantial improvements in the effectiveness of diagnosis and treatment, there are certain aspects that represent unwavering predicaments of the current gastroenterology practice. A detailed list includes difficulties and risks, such as transmission of communicable diseases (e.g., COVID-19) due to the doctor–patient proximity, unchanged learning curves, variable detection rates, procedure-related adverse events, endoscopists’ and nurses’ burnouts, limited human and/or material resources, and patients’ preferences to choose non-invasive options that further interfere with the successful implementation and adoption of routine screening. The combination of robotics and artificial intelligence, as well as remote telehealth endoscopy services, are also discussed, as viable solutions to improve existing platforms for diagnosis and treatment are emerging.


  • Open Access

    Balloon-Assisted Colonoscopy after Incomplete Conventional Colonoscopy—Experience from Two European Centres with A Comprehensive Review of the Literature

    by Robertson Alexander R, Koulaouzidis Anastasios, Yung Diana E, Fraser Christopher, Nemeth Artur, Trimble Kenneth, Toth Ervin, Plevris John N, Wurm Johansson Gabriele

    Background: Conventional colonoscopy (CC) allows access for colonic investigation and intervention; in the small group in whom CC is unsuccessful alternative imaging is often sufficient. There remains a subset, however, requiring full colonic visualisation or intervention. Balloon-assisted colonoscopy (BAC) gives a further option when access is difficult. Aims: This study aims to present the experience with BAC of two European tertiary referral centres. Methods: Procedures were carried out under local protocol over 15-years (2006–2020). Markers of procedural quality such as caecal intubation, complications and comfort were retrospectively compiled and analysed. Published evidence was summarised for comparison. Results: 122 procedures were undertaken, with polyps the most frequent indication and 90.2% having at least one previously incomplete CC. Features associated with difficult colonoscopy were common, including intraabdominal surgery (32.0%). 92.6% reached the caecum; completion was higher (96.3%) in those failing CC due to discomfort and lower in those failing due to anatomical difficulties (90.7%) or previous surgery (84.6%). Mean time to the caecum was 20.9 minutes and mean midazolam and fentanyl doses were 2.6 mg and 49.9 µg with low discomfort scores. Conclusion(s): Balloon-assisted colonoscopy is successful in >90% of patients, is well-tolerated, and is safe.


  • Open Access

    Small bowel angioectasia as a marker of frailty and poor prognosis

    by Alexander R. Robertson, Anastasios Koulaouzidis, William M. Brindle, Andrew J. Robertson, John N. Plevris

    Background and study aims This study aimed to establish 5-year survival of patients diagnosed with bleeding small bowel (SB) angioectasia, with the hypothesis that many will suffer deaths relating to comorbidity rather than gastrointestinaI bleeding. Patients and methods SB capsule endoscopy (SBCE) procedures, performed for suspected SB bleeding or iron deficiency anemia, with angioectasia isolated as the cause of SB bleeding and at least 5 years of follow-up data were isolated (n = 125) along with an age-matched group with "normal" SBCE procedures (n = 125). These were retrospectively analysed with further information on mortality and comorbidity gathered through hospital records. Results Those with angioectasia had a median age of 72.7 years and comorbidities were common. The 5-year survival was 64.0 % (80/125) compared to 70.4 % (88/125) in those with "normal" SBCE. Those with significant cardiac or vascular comorbidity had a poorer survival (52.9 % (37/70) at 5 years) but anticoagulation/antiplatelets/ number of lesions or requirement endoscopic treatment seemed to make little difference. In those with SB bleeding secondary to angioectasia none of the subsequent deaths were directly attributable to gastrointestinal bleeding. Conclusions In this cohort, SB angioectasia did not lead to any deaths but the 5-year survival was poor due to those diagnosed often being older and having comorbidities. This would support the hypothesis that a diagnosis of SB bleeding secondary to angioectasia suggests frailty.


  • Open Access

    Faecal Calprotectin and 7-α Cholestenone Levels in Microscopic Colitis: Experience from Edinburgh

    by Matt Davie, Rebecca Trimble, Alexander R Robertson, Anastasios Koulaouzidis

    Introduction: Microscopic colitis (MC) is an important cause of chronic, watery diarrhoea. Currently, there is no specific biomarker available to guide diagnosis. The use of faecal calprotectin (FCP) as a potential marker has been addressed in only a few studies. Further, bile acid malabsorption (BAM) often accompaniesMC. Current practice recommends the selenium-labelled homocholic acid-taurine (SeHCAT) test, but at our centre, 7 alpha-hydroxy-4-cholesten-3-one (7 alpha C) is used as a simpler and less expensive alternative to SeHCAT, with values over 22ng/mL indicating BAM. This study aims to evaluate the use of FCP as a biomarker in the diagnosis of MC and the role of 7 alpha C in detecting concomitant BAM with MC. Methods: Pathology records were retrospectively reviewed for patients diagnosed with collagenous colitis (CC) between 2000 and 2018 and lymphocytic colitis (LC) between 1995 and 2011. FCP and 7 alpha C results, if measured within 6 months of pathological diagnosis, were extracted for analysis. Results: Between 2000 and 2018, 646 CC cases were confirmed on histology. Of 646 patients, 147 had FCP measured; in 111 (75.5%) FCP was elevated with mean levels 238.1 mu g/g (SD +/- 273.0); 140/646 had 7 alpha C measured; 16 (11.4%) indicated BAM. Mean levels were 10.2ng/mL (SD +/- 9.4). During a 21-year period (1995-2011), 204 LC diagnoses were made: 14/204 had FCP measured; 8 (57.1%) were elevated. Mean levels were 128.4 mu g/g (SD +/- 107.7). Of 204 LC patients, 20 had 7 alpha C measured, 5 (25%) indicating BAM. Mean levels were 13.95ng/mL (SD +/- 9.4). Discussion: Both CC and LC were associated with raised FCP during the diagnostic phase, supporting the potential role of its use in clinical practice. Furthermore, we present results of using 7 alpha C in identifying BAM amongst patients with MC. In our cohort, low levels of 7 alpha C suggest relatively low concordance of BAM with MC.


  • What Becomes of the Frequent Hospital Attenders with Centrally Mediated Gastrointestinal Pain Syndrome?

    by Alexander R. Robertson

    Objective: Centrally mediated gastrointestinal pain syndrome (CAPS) is an infrequently diagnosed functional condition. A small number of patients do, however, become heavy service users due to difficulty in controlling severe symptoms. We aim to review the outcomes of patients who required frequent hospitalisation with CAPS. Methods: Medical records of patients with multiple CAPS presentations during 2015 (n = 18) were further analysed and reviewed until January 1st, 2019. Results: Patients (female 15; male 3) had a median age of 33 (IQR 12) years. Gastrointestinal co-diagnosis was common (88.9%), most frequently irritable bowel syndrome (50%), cyclical vomiting syndrome (27.8%) or gastro-oesophageal reflux disease (16.7%). 66.7% were prescribed regular opiate analgesics. Psychiatric co-morbidity was present in almost all: depression (88.9%); anxiety/panic disorders (38.9%) and post-traumatic stress disorder (27.8%). Social stressors were cited in 33.3%. 27.8% were employed, frequently in healthcare. Over the 4-year study period, 18 identified patients accounted for 2,048 nights in hospital and 672 A+E attendances. In 2015, these patients spent a median of 19 (IQR 34) nights in hospital each with median hospitalisations of between 7 and 10 nights over the following 3 years. Median A+E attendance was 8 per patient (IQR 8) in 2015, remaining relatively constant between 5 and 6 A+E presentations per patient per subsequent year. Conclusion: CAPS is a complicated heterogenous condition resulting from an interplay of physical stimuli with cognitive and emotional factors. As such, management is difficult and requires a multidisciplinary approach with considerable patient ownership of the condition, which is often difficult to achieve.