The rise of robotic colorectal surgery: better for patients and better for surgeons

Robotic colorectal surgery represents a major technological advancement in the treatment of patients with colorectal disease. Several recent randomized controlled trials comparing robotic colorectal surgery with laparoscopic surgery have demonstrated improved short-term patient outcomes in the robotic group. Whilst the primary focus of research in robotic surgery has been on patient outcomes, the robotic platform also provides unparalleled benefits for the surgeon, including improved ergonomics and surgeon comfort, with the potential to reduce occupational injuries and prolong career longevity. It is becoming clear that robotic surgical systems improve patient outcomes and may provide significant benefits to the surgical workforce.

Sigmoid Diverticulitis in a Tight Spot: An Atypical Presentation Within a Ventral Hernia

Ventral hernia and acute diverticulitis may present with similar symptoms posing difficulty in clinical diagnosis. Rarely, complicated sigmoid diverticulitis is found within an irreducible ventral hernia sac in the emergency setting. Intraoperative decision on the appropriate surgical option depends on the surgeon's experience and the patient's clinical state. We present a case of a middle-aged female who came in with infraumbilical hernia containing necrotic sigmoid diverticulitis. Her surgical history was cesarean section and total abdominal hysterectomy with a re-look laparotomy. She had an emergency exploration of the hernia through a midline incision, excision of the necrotic diverticulum, and the formation of loop colostomy at the site of the hernia. Post-operative recovery was uneventful and she has been scheduled for an elective sigmoid colectomy and reversal of the stoma. This study highlights that complicated sigmoid diverticulitis can rarely present as an irreducible ventral hernia and that less is often more in safely getting patients out of trouble in an emergency.

Methylene blue fluorescence of the ureter during colorectal surgery

Background

Iatrogenic ureteric injury is a serious complication of colorectal surgery. Incidence is estimated to be between 0.3 and 1.5%. Of all ureteric injuries, 9% occur during colorectal procedures. Ureteric stents are utilised as a method to reduce the risk of injury; however, these are not without risk and do not guarantee prevention of injury. Fluorescence is a safe and effective alternative for intraoperative ureteric localisation. This proof of principle study aims to assess the use of methylene blue to fluoresce the ureter during colorectal surgery.

Method

Patients undergoing elective colorectal surgery were included in this open label, non-randomised study. Methylene blue was administered intravenously at varying doses (0.25–1 mg/kg) over 5 min, 10–15 min prior to entering ‘ureteric territory.’ Fluorescence was assessed using the PINPOINT Deep Red laparoscopic system at fixed time points by the surgeon and an independent observer.

Results

42 patients received methylene blue; 2 patients were excluded from analysis. Of the 69 ureters assessed, 64 were seen under fluorescence. Of these, 14 were not visible under white light. 50 ureters were observed with both fluorescence and white light with 14 of these being seen earlier with fluorescence. In ten cases, fluorescence revealed the ureter to be in a different location than suspected.

Conclusion

Fluorescence is a promising method to allow visualisation of the ureter, where it is not identified easily under standard operative conditions, thereby improving safety and reducing operative time and difficulty.

Electronic supplementary material

The online version of this article (10.1007/s00464-018-6219-8) contains supplementary material, which is available to authorized users.

Intraoperative identification and analysis of lymph nodes at laparoscopic colorectal cancer surgery using fluorescence imaging combined with rapid OSNA pathological assessment

Background

Standard surgical practice for colorectal cancer involves resection of the primary lesion and all draining lymph nodes. Accurate intraoperative assessment of nodal status could allow stratified resectional extent. One-step nucleic acid (OSNA) can provide a rapid method of interrogating nodal tissue, whilst near-infrared (NIR) laparoscopy together with indocyanine green (ICG) can identify relevant nodal tissue intraoperatively.

Methods

ICG was administered around the tumour endoscopically prior to the operation. Fluorescent nodes identified by NIR were marked and submitted for whole-node OSNA analysis. Further fresh lymph nodes dissected from the standard resection specimen were examined and analysed by both conventional histology and OSNA. In addition, the status of the fluorescent nodes was compared to that of non-ICG nodes to assess their predictive value.

Results

Sixteen patients were recruited with a total final lymph node count of 287. 78 fresh lymph nodes were identified on fresh dissection for both histological and OSNA assessment with an analytical concordance rate of 98.7% (77/78). OSNA sensitivity was 1 (0.81–1, 95% CI) and specificity 0.98 (0.91–1, 95% CI). Six patients had a total of nine nodes identified intraoperatively by ICG fluorescence. Of these nine nodes, one was positive for metastasis on OSNA. OSNA analysis of the ICG-labelled node matched the final histological nodal stage in 3/6 patients (two being N0 and one N1). The final pathological nodal stage of the other three was N1 or N2, while the ICG nodes were negative.

Conclusion

OSNA is highly concordant with standard histology, although only a minority of nodes identifiable by full pathological analysis were found for OSNA on fresh dissection. OSNA can be combined with NIR and ICG lymphatic mapping to provide intraoperative assessment of nodal tissue in patients with colorectal cancer.

Fluorescence angiography in laparoscopic low rectal and anorectal anastomoses with pinpoint perfusion imaging--a critical appraisal with specific focus on leak risk reduction

BACKGROUND AND AIMS

Anastomotic dehiscence is one of the most feared complications in colorectal surgery leading to significant morbidity and mortality. Progressively lower anastomoses are associated with a greater leak rate. One of the key factors is the perfusion of the bowel to be joined. Presently, surgeons rely on a variety subjective measures to determine anastomotic perfusion and mechanical integrity however these have shortcomings. The aim of this paper is to appraise the literature on the use of fluorescence angiography (FA) in laparoscopic rectal surgery.

MATERIALS AND METHODS

A Pubmed search was undertaken using terms 'fluorescence angiography' and 'rectal surgery'. The search was expanded using the related articles function. Studies were included if they used FA specifically for rectal surgery. Outcomes of interest including anastomotic leak rate, change of operative strategy and time taken for FA were recorded.

RESULTS

Eleven papers detailing the use of FA in rectal surgery are outlined demonstrating that this technique may change operative strategy and lead to a reduction in anastomotic leak rate.

CONCLUSION

In this paper, we discuss assessment of colorectal blood supply using FA and how this technique holds great potential to detect insufficiently perfused bowel. In so doing, the operator can adjust their operative strategy to mitigate these affects with the aim of reducing the complications of anastomotic leak and stenosis. However, it is highlighted that there is a clear need for randomised controlled trials in order to determine this definitively.

Assessment of the quality of patient-orientated internet information on surgery for ulcerative colitis

AIM

This study examines the quality of websites providing information on ulcerative colitis, including treatment options and surgery.

METHOD

Two search engines (Google and Yahoo) and the search term 'surgery for ulcerative colitis' were used. The first 50 sites obtained with each search engine were assessed. Sites were evaluated for content and scored using the DISCERN instrument, which evaluates the quality of health information on treatment choices.

RESULTS

One hundred sites were examined, of which 14 were duplicates. Of the remainder, 58 provided patient-orientated information for adults and one site provided information for surgery in children. The other 27 sites included six scientific articles, three blogs, three links, six resources for clinicians, five fora, two video links and two dead links. Of the 58 websites that provided patient information for adults, only 26 (44.8%) had been updated within the last 2 years. Only 13/58 (22.4%) were affiliated to hospitals and clinics. Most sites (38/58, 65.5%) were associated with private companies with commercial interests. Although most websites contained information on symptoms and treatment options for ulcerative colitis, 37 (63.8%) did not describe any of the risks of surgery. Overall, only seven (12.1%) websites were identified as being 'good' or 'excellent' using the DISCERN criteria.

CONCLUSION

The quality of patient information on surgery for ulcerative colitis is highly variable. There is potential for internet provision of valuable information and clinicians should guide patients with to access high-quality websites.

Quality analysis of patient information on surgical treatment of haemorrhoids on the internet

INTRODUCTION

Haemorrhoids are the most common benign condition seen by colorectal surgeons. At clinic appointments, advice given about lifestyle modification or surgical interventions may not be understood fully by patients. Patients may use the internet for further research into their condition. However, the quality of such information has not been investigated before. This study assessed the quality of patient information on surgical treatment of haemorrhoids on the internet.

METHODS

Four searches were carried out using the search terms 'surgery for haemorrhoids' and 'surgery for piles' on two search engines (Google and Yahoo). The first 50 results for each search were assessed. Sites were evaluated using the DISCERN instrument.

RESULTS

In total, 200 websites were assessed, of which 144 fulfilled the inclusion criteria. Of these, 63 (44%) were sponsored by herbal remedies for haemorrhoids. Eighty-nine (62%) mentioned conservative treatment options but eleven (8%) did not include surgery in their treatment options. Only 38 sites (27%) mentioned recurrence of haemorrhoids following surgery and 28 sites (20%) did not list any complications. Overall, 19 websites (14%) were judged as being of high quality, 66 (45%) as moderate quality and 58 (40%) as low quality.

CONCLUSIONS

The quality of information on the internet is highly variable and a significant proportion of websites assessed are poor. The majority of websites are sponsored by private companies selling alternative treatments for haemorrhoids. Clinicians should be prepared to advise their patients which websites can provide high-quality information on the surgical treatment of haemorrhoids.

Stem cell differentiation and lumen formation in colorectal cancer cell lines and primary tumors

Single cancer stem-like cells (CSC) from colorectal cancers can be functionally identified by their ability to form large lumen-containing colonies in three-dimensional Matrigel cultures. These colonies contain the three types of differentiated colorectal epithelial cells, and single cells obtained from them can reproduce themselves and form tumors efficiently in immunodeficient mice. In this study, we show how hypoxia affects these CSC-derived lumens to control differentiation of stem-like cells and enterocytes via the homeobox gene CDX1. Lumens were identified by F-actin staining and they expressed many characteristics associated with normal differentiated intestinal epithelium, including brush border enzymes, polarization, and tight junctions. RNA interference-mediated silencing of CDX1 reduced lumen formation. Inhibitory effects of hypoxia on lumen formation and stem cell differentiation, including suppression of CDX1 expression, could be mimicked by inhibiting prolyl-hydroxylases that activate HIF1, suggesting that HIF1 is a critical mediator of the effects of hypoxia in this setting. Cell line-derived lumens were phenotypically indistinguishable from colorectal tumor glandular structures used by pathologists to grade tumor differentiation. Parallel results to those obtained with established cell lines were seen with primary cultures from fresh tumors. This in vitro approach to functional characterization of CSCs and their differentiation offers a valid model to study colorectal tumor differentiation and differentiation of colorectal CSCs, with additional uses to enable high-throughput screening for novel anticancer compounds.

What is the potential of oligodendrocyte progenitor cells to successfully treat human spinal cord injury?

Background

Spinal cord injury is a serious and debilitating condition, affecting millions of people worldwide. Long seen as a permanent injury, recent advances in stem cell research have brought closer the possibility of repairing the spinal cord. One such approach involves injecting oligodendrocyte progenitor cells, derived from human embryonic stem cells, into the injured spinal cord in the hope that they will initiate repair. A phase I clinical trial of this therapy was started in mid 2010 and is currently underway.

Discussion

The theory underlying this approach is that these myelinating progenitors will phenotypically replace myelin lost during injury whilst helping to promote a repair environment in the lesion. However, the importance of demyelination in the pathogenesis of human spinal cord injury is a contentious issue and a body of literature suggests that it is only a minor factor in the overall injury process.

Summary

This review examines the validity of the theory underpinning the on-going clinical trial as well as analysing published data from animal models and finally discussing issues surrounding safety and purity in order to assess the potential of this approach to successfully treat acute human spinal cord injury.

Regulation of self-renewal and differentiation by the intestinal stem cell niche

The gastrointestinal epithelium is a highly organised tissue that is constantly being renewed. In order to maintain homeostasis, the balance between intestinal stem cell (ISC) self-renewal and differentiation must be carefully regulated. In this review, we describe how the intestinal stem cell niche provides a unique environment to regulate self-renewal and differentiation of ISCs. It has traditionally been believed that the mesenchymal myofibroblasts play an important role in the crosstalk between ISCs and the niche. However, recent evidence in Drosophila and in vertebrates suggests that epithelial cells also contribute to the niche. We discuss the multiple signalling pathways that are utilised to regulate stemness within the niche, including members of the Wnt, BMP and Hedgehog pathways, and how aberrations in these signals lead to disruption of the normal crypt-villus axis. Finally, we also discuss how CDX1 and inhibition of the Notch pathway are important in specifying enterocyte and goblet cell differentiation respectively.

Advances in endoscopic visualization of colorectal polyps

AIM

Conventional white-light endoscopy is currently the gold standard for the detection and treatment of colorectal polyps. However, up to a fifth of polyps may be missed on initial examination, especially flat and small mucosal lesions. This study reviews the literature reporting on the use of new advances in endoscopic visualization.

METHOD

Literature searches were performed on PubMed using the terms 'chromoendoscopy', 'narrow-band imaging' (NBI), 'autofluorescence imaging' (AFI), 'Fujinon Intelligent Colour Enhancement' (FICE), 'i-Scan colonoscopy', 'zoom colonoscopy' and 'confocal laser endomicroscopy' (CLE). We focused on systematic reviews, national guidelines and randomized controlled trials written in English. Studies were assessed for methodological quality using QUADAS. Prospective studies assessing new technology were also reviewed. Further publications were identified from reference lists.

RESULTS

Chromoendoscopy increases the detection of neoplastic polyps compared with conventional colonoscopy. NBI avoids the use of additional dyes and enhances the vascular network of capillaries surrounding the crypts, increasing the adenoma detection rate and the ability to distinguish between neoplastic and non-neoplastic lesions. FICE, AFI and i-Scan are new developments that improve tissue contrast. Zoom endoscopy may be combined with different modalities to help further characterize colonic lesions. CLE provides live in vivo high-resolution optical sections of tissue and may be particularly useful in the surveillance of patients with long-standing ulcerative colitis, reducing the number of random biopsies.

CONCLUSION

Although there is mounting evidence that these new technologies are superior to conventional endoscopy, current guidelines are limited. Further large-scale randomized controlled trials comparing these modalities in different patient subpopulations are warranted.

Colorectal cancer stem cells

PURPOSE

The cancer stem cell hypothesis predicts that only a subpopulation of cells within a tumor is responsible for driving growth. If this hypothesis were true, it would have a significant impact on our current treatment of cancer because conventional chemotherapy and radiotherapy target rapidly proliferating cells making up the bulk of the tumor, not specifically cancer stem cells. The aims of this review are to highlight the current evidence supporting the existence of cancer stem cells in colorectal cancer, to consider the relative merits of current cancer stem cell markers, and to discuss the implications of this on our current treatment of cancer.

METHODS

Published scientific articles were selected by searching the PubMed database by use of the terms "colorectal," "cancer," and "stem cells," and by use of the bibliographies of extracted articles.

RESULTS AND CONCLUSION

CD133, a glycosylated cell surface protein, has been demonstrated to isolate for a subpopulation of colorectal tumor cells enriched in cancer stem cells. However, only 1 in 262 CD133+ cells are able to initiate tumors. Other cancer stem cell markers have been investigated, but an overall need exists to identify more specific markers to allow further characterization of these cancer stem cells. We discuss how increased understanding of the distribution and behavior of cancer stem cells within tumors could have significant implications for the management of colorectal cancer, including screening, resection margins, sentinel node biopsy, determination of prognosis, and the development of novel therapeutic targets.

Orthotopic liver transplantation for subacute hepatic failure following partial treatment of isoniazid-resistant tuberculosis

The management of patients with pre-existing tuberculosis (TB) undergoing liver transplantation is challenging. Cautious immunosuppression is required to prevent reactivation of disease, and second-line anti-tuberculous treatment may be necessary to prevent graft hepatotoxicity. Furthermore, liver transplantation in the context of isoniazid-resistant TB has seldom been reported. We report on a 44-year-old man with recent isoniazid-resistant extra-pulmonary TB who developed subacute hepatic failure requiring emergency liver transplantation and treatment with second-line anti-tuberculous therapy. We demonstrate that patients who have pre-existing TB can be successfully treated with alternative anti-tuberculous medication while under immunosuppression post transplantation. Pre-existing TB, including resistant strains, should not be an absolute contraindication to liver transplantation.