Maximum Entropy (Most Likely) Double Helical and Double Logarithmic Spiral Trajectories in Space-Time.

The ubiquity of double helical and logarithmic spirals in nature is well observed, but no explanation is ever offered for their prevalence. DNA and the Milky Way galaxy are examples of such structures, whose geometric entropy we study using an information-theoretic (Shannon entropy) complex-vector analysis to calculate, respectively, the Gibbs free energy difference between B-DNA and P-DNA, and the galactic virial mass. Both of these analytic calculations (without any free parameters) are consistent with observation to within the experimental uncertainties. We define conjugate hyperbolic space and entropic momentum co-ordinates to describe these spiral structures in Minkowski space-time, enabling a consistent and holographic Hamiltonian-Lagrangian system that is completely isomorphic and complementary to that of conventional kinematics. Such double spirals therefore obey a maximum-entropy path-integral variational calculus ("the principle of least exertion", entirely comparable to the principle of least action), thereby making them the most likely geometry (also with maximal structural stability) to be adopted by any such system in space-time. These simple analytical calculations are quantitative examples of the application of the Second Law of Thermodynamics as expressed in geometric entropy terms. They are underpinned by a comprehensive entropic action ("exertion") principle based upon Boltzmann's constant as the quantum of exertion.

Self-expandable metal stents for obstructing colonic and extracolonic cancer: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline

This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). This Guideline was also reviewed and endorsed by the Governing Board of the American Society for Gastrointestinal Endoscopy (ASGE). The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations The following recommendations should only be applied after a thorough diagnostic evaluation including a contrast-enhanced computed tomography (CT) scan. 1 Prophylactic colonic stent placement is not recommended. Colonic stenting should be reserved for patients with clinical symptoms and imaging evidence of malignant large-bowel obstruction, without signs of perforation (strong recommendation, low quality evidence). 2 Colonic self-expandable metal stent (SEMS) placement as a bridge to elective surgery is not recommended as a standard treatment of symptomatic left-sided malignant colonic obstruction (strong recommendation, high quality evidence). 3 For patients with potentially curable but obstructing left-sided colonic cancer, stent placement may be considered as an alternative to emergency surgery in those who have an increased risk of postoperative mortality, I. e. American Society of Anesthesiologists (ASA) Physical Status ≥ III and/or age > 70 years (weak recommendation, low quality evidence). 4 SEMS placement is recommended as the preferred treatment for palliation of malignant colonic obstruction (strong recommendation, high quality evidence), except in patients treated or considered for treatment with antiangiogenic drugs (e. g. bevacizumab) (strong recommendation, low quality evidence).(AU)

Colo-vesical fistula: Complete healing without surgical intervention.

INTRODUCTION: Colo-vesical (CV) fistulae are the most common type of fistulae associated with diverticular disease. Surgery remains the mainstay of treatment, without which, CV fistulae rarely achieve complete healing. PRESENTATION OF CASE: Herein, we report the case of a 62-year-old man who developed a CV fistula after reversal of Hartmann's procedure (initially for management of diverticular abscess), which healed with conservative management alone. DISCUSSION: We discuss possibilities of the aetiology of this fistula. The CV fistula may have been initially present, which came to light only after his reversal. Or an iatrogenic fistula that developed at the time of reversal of Hartmann's. CONCLUSION: This is the first time that such a fistula has been demonstrated clinically and radiologically to have healed spontaneously without surgery. We recommend that conservative management of CV fistulae should be considered.

The application of TachoSil® for sealing colorectal anastomosis: a feasibility study.

AIM: Anastomotic leakage is a frequent postoperative complication of colorectal resection. This nonrandomized study assessed the feasibility and safety of applying a haemostatic tissue sealant (TachoSil®) to colorectal anastomoses following resection. METHOD: TachoSil was applied as reinforcement of the anastomotic line after laparoscopic or open colorectal resection. The primary endpoint was the proportion of patients for whom TachoSil application was considered feasible by both the investigator and an independent external assessor. Application was considered feasible if TachoSil fully adhered, covered ≥1cm beyond the margin of the anastomotic line and patches overlapped by ≥1cm. Individual investigator assessment of feasibility and adverse events 30 days after surgery were also recorded. RESULTS: Twenty-five patients underwent anterior resection (seven open lower, nine open middle-upper, four laparoscopic lower and five laparoscopic middle-upper). In six cases a video-recording was not available because of technical problems. The primary endpoint was met in 12 of the remaining 19 patients (63%; 95% CI 38-84%), while in the other seven the application was recorded as not feasible because the assessor was unable to see the entire anastomosis. No application was assessed as unfeasible on the basis of visual evidence. When assessed by the investigator alone, TachoSil was considered feasible in all but one instance (96%; 95% CI 80-100%). There were 45 adverse events, of which 10 were serious. None was considered related to TachoSil. No deaths were reported. CONCLUSION: Application of TachoSil to reinforce the anastomotic line in colorectal resections appears to be feasible and well tolerated.

Laparoscopic slit mesh repair of parastomal hernia using a designated mesh: long-term results.

BACKGROUND: Parastomal hernia (PH) is a frequent complication of colorectal surgery, which incidence reaches 55% of all stoma formation. Currently, there is no definitive strategy for its repair. This study was designed to assess the outcome in patients who underwent laparoscopic PH repair using a slit mesh/keyhole technique. METHODS: We undertook a retrospective case review of all patients who underwent laparoscopic PH repair with a designed slit mesh/keyhole between 2005 and 2010. Three ports were placed opposite the stoma site, and careful adhesiolysis and hernia content reduction were performed. The parastomal fascial defect was measured and covered with a designated mesh. Fixation of the mesh was achieved with concentric tacks and transcutaneous Prolene suture. Recurrence was diagnosed after examination of patients by two surgeons or by imaging demonstrating an indolent hernia. RESULTS: Twenty-nine laparoscopic PH mesh repairs were performed with an average age of 63.5 (range 42-81, median 64) years to treat paracolostomy hernia in 18 of 29 cases (62.1%), para-ileostomy hernia in 10 of 29 cases (34.5%), and for an ileal conduit site hernia in 1 of 29 cases (3.4%). The average operative time was 179 (range, 80-300; median, 180) min. Two operations (6.9%) were converted to an open approach. Early postoperative complications were documented in four patients (13.8%), including one elderly patient with severe comorbidities who died from postoperative sepsis (mortality rate, 3.4%). Only one late complication was recorded (3.4%). The average hospital stay was 4.7 (range, 1-19; median, 3) days. Average follow-up time was 28 (range, 12-53; median, 30) months. Recurrence of the hernia was found in 13 of 28 patients (46.4%). CONCLUSIONS: Laparoscopic slit mesh/keyhole repair is feasible, although it is a complex surgery reflected by extended operative time. The high recurrence rate suggests that technical improvement of the method is essential.

Bilateral ischaemic optic neuropathy following laparoscopic proctocolectomy: a case report.

INTRODUCTION: Perioperative visual loss occurring during non-ocular surgery is a devastating event. Ischaemic optic neuropathy (ION) is a complication described following many procedures. We report the first case of ION occurring during laparoscopic proctocolectomy and discuss the aetiological factors. CASE HISTORY: A 58-year-old male presented with rectal bleeding and was diagnosed with an adenocarcinoma of the sigmoid colon. A very difficult laparoscopic sigmoidectomy and a low anterior resection of the rectum with an end colostomy were carried out. The technical difficulties were due to body habitus and the size and position of the tumour. The operation lasted over six hours. On the first day postoperatively, the patient complained of blurred vision. Examination showed that he had suffered bilateral ION. DISCUSSION: Despite the growing numbers of laparoscopic operations, ION has rarely been described. The cases that were published involved laparoscopic prostatectomy and a prolonged steep Trendelenburg position. We postulate that the patient presented here had suffered both from a relative hypotension and from an acute rise in the intraorbital pressure due to patient position, both factors combining to cause a disruption to ocular perfusion resulting in ION with severe permanent visual damage.

Case controlled study of the hospital stay and return to full activity following laparoscopic and open colorectal surgery before and after the introduction of an enhanced recovery programme.

AIM: The short-term benefits of laparoscopic surgery are well established and in particular within an enhanced recovery programme. Early return to activity is to be expected but has not been quantified widely. The aim of this study was to measure the hospital stay and return to full activity following laparoscopic colorectal surgery and compare this with a matched group of patients undergoing open colorectal resections before and after the introduction of an enhanced recovery programme. METHOD: Retrospective analysis of all laparoscopic colorectal operations performed between January 2003 and June 2007 on an intention to treat basis compared with a matched group of patients undergoing elective open colorectal surgery at the same institution. RESULTS: The median hospital stay following 179 laparoscopic colorectal resections was 6 days whilst following 144 conventional open operations it was 8 days. Following the introduction of an enhanced recovery programme the hospital stay fell from 7 to 5 days and from 9 to 7 days for laparoscopic and open groups respectively. The median return to full activity from surgery for laparoscopic patients was 13 days in comparison to 56 days for patients undergoing open colorectal surgery. CONCLUSIONS: Following laparoscopic colorectal resection, patients can be expected to have a hospital stay of under a week and return to their usual activities as early as a week after discharge from hospital and < 2 weeks from surgery in comparison to patients undergoing open surgery who take 8 weeks or more to recover.

Adhesions and incisional hernias following laparoscopic versus open surgery for colorectal cancer in the CLASICC trial.

BACKGROUND: This study investigated adhesive intestinal obstruction (AIO) and incisional hernia (IH) in patients undergoing laparoscopically assisted and open surgery for colorectal cancer. METHODS: In a case-note review of patients randomized to the Medical Research Council's Conventional versus Laparoscopic-Assisted Surgery In Colorectal Cancer (CLASICC) trial, primary and key secondary endpoints were AIO and IH admission rates respectively. RESULTS: Of 411 patients, 11 were admitted for AIO: four (3.1 per cent) of 131 patients in the open arm of the trial versus seven (2.5 per cent) of 280 in the laparoscopic arm (difference 0.6 (95 per cent confidence interval (c.i.) - 2.9 to 4.0) per cent). Thirty-six patients developed IH: 12 (9.2 per cent) after open versus 24 (8.6 per cent) after laparoscopic surgery (difference 0.6 (95 per cent c.i. - 5.3 to 6.5) per cent). Results by actual procedure showed higher AIO and IH rates in the 24.5 per cent of patients who converted from laparoscopic to open surgery (AIO: 2.3, 2.0 and 6 per cent; IH: 8.6, 7.4 and 11 per cent-for open, laparoscopic and converted operations respectively). CONCLUSION: Although this study has not confirmed that laparoscopic surgery reduces rates of AIO and IH after colorectal cancer surgery, trends suggest that a reduction in conversion to open surgery and elimination of port-site hernias may produce such an effect. Registration number for CLASICC trial: ISRCTN74883561 (http://www.controlled-trials.com).

Consensus statement: natural orifice transluminal endoscopic surgery.

Natural orifice transluminal endoscopic surgery (NOTES) has generated healthy and vigorous debate about the introduction of an entirely novel method of surgical therapy. Although there are many reasons for scepticism, there is undoubted interest in this field from both the medical profession and general public. Those Associations currently involved in laparoscopic and endoscopic surgery wish to safeguard patients and the reputation of the profession by issuing clear guidance and support for those wishing to undertake NOTES. The purpose of this document is to review the current status of both NOTES and hybrid NOTES, while at the same time identifying obstacles in both clinical research and training. Furthermore, it aims to provide a consensus statement on behalf of the main UK specialty associations involved in this field of surgery. The primary aim of this consensus statement is to provide a framework within which to develop, safely and effectively, what must still be considered an experimental technique.

Combined endoscopic trans-anal rectal mucosal ablation and laparoscopic partial proctectomy for ulcerative colitis--a new procedure.

A case is reported in which endoscopic trans-anal rectal mucosal ablation (ETARMA) was employed in combination with laparoscopic partial proctectomy in order to decrease complications associated with open surgery.

Self-expanding metallic stents in the treatment of benign colorectal anastomotic strictures: a word of caution.

A 66-year-old man underwent an anterior resection for carcinoma at the rectosigmoid junction. Three months later, a tight stricture developed proximal to the anastomosis. This was treated with a self-expanding metallic stent. Over the next few months, the stent fractured and a fistula developed between the site of anastomic stricture and the distal ileum; the stent had to be removed. This, to our knowledge, is the first report of a coloenteric fistula developing after insertion of a metallic stent to treat a benign postoperative anastomotic stricture.

Comparison of short-and long-term outcomes following either insertion of self-expanding metallic stents or emergency surgery in malignant large bowel obstruction.

BACKGROUND: Self-expanding metallic stents (SEMS) are now regarded as a safe and effective treatment for an acute obstructing colorectal cancer. SEMS insertion is an invasive procedure that could potentially worsen prognosis. This study assessed the short-and long-term outcomes in patients stented for acute large bowel obstruction and in patients who underwent primary emergency surgery. METHODS: We retrospectively identified 19 patients who underwent SEMS insertion and 23 patients who had primary emergency surgery for left-sided large bowel obstruction as the first presentation of colorectal cancer. RESULTS: There were no significant differences between the 19 patients in the SEMS group and the 23 patients in the primary emergency surgery group in terms of demographics and tumour location and stage. Stent insertion was successful in 16 patients (84%). One patient died from a stent-related perforation and another had a stoma fashioned for stent migration. Stents were a definitive procedure in 2 patients with advanced disease and acted as a "bridge to surgery" in the remaining 12 patients. Compared to the primary surgery group, there was a trend towards a higher primary anastomosis rate in the SEMS group (p=0.08); there were no significant differences in length of hospital stay, 30-day mortality or complication rates between the groups. Long-term prognosis (estimated 3-year survival) did not differ significantly between the groups (p=0.54); this persisted when only curative resections were considered (p=0.80). CONCLUSIONS: Preoperative stent insertion is a safe and effective treatment for large bowel obstruction, and may result in a higher primary anastomosis rate. Stent insertion does not seem to have a deleterious effect on prognosis.

Laparoscopic management of iatrogenic bladder injury and bladder stone formation following laparoscopic inguinal herniorrhaphy.

BACKGROUND: Herniorrhaphy is one of the most commonly performed operations in the UK. Approximately 1 per 1,000 of the population has a groin hernia. METHOD AND RESULT: We report on a rare complication following laparoscopic inguinal herniorrhaphy of bladder stone formation and its management. CONCLUSION: To our knowledge a combined laparoscopic repair of the urinary bladder wall, following iatrogenic injury by a mesh fixation clip and retrieval of bladder stone (induced through the misplacement of the clip) has not been described previously.

Impact of adhesions in colorectal surgery.

The extent of the problem of adhesions is considerable and poses a significant burden on healthcare systems, the workload of surgeons and the lives of patients. This paper reviews the work undertaken and the associated evidence for the impact of adhesions. It considers the various options and strategies to reduce adhesions alongside the fundamental necessity for good surgical technique.

Adhesions and colorectal surgery - call for action.

Mounting evidence highlights that adhesions are now the most frequent complication of abdominopelvic surgery, yet many surgeons are still not aware of the extent of the problem and its serious consequences. While many patients go through life without apparent problems, adhesions are the major cause of small bowel obstruction and a leading cause of infertility and chronic pelvic pain in women. Moreover, adhesions complicate future abdominal surgery with important associated morbidity and expense and a considerable risk of mortality. Studies have shown that despite advances in surgical techniques in recent years, the burden of adhesion-related complications has not changed. Adhesiolysis remains the main treatment even though adhesions reform in most patients. Recent developments in adhesion-reduction strategies and new anti-adhesion agents do, however, offer a realistic possibility of reducing the risk of adhesions forming and potentially improving the clinical outcomes for patients and reducing the associated onward burden to healthcare systems. This paper provides a synopsis of the impact and extent of the problem of adhesions with reference to the wider literature and also consideration of the key note papers presented in this special supplement to Colorectal Disease. It considers the evidence of the risk of adhesions in colorectal surgery and the opportunities and strategies for improvement. The paper acts as a 'call for action' to colorectal surgeons to make prevention of adhesions more of a priority and importantly to inform patients of the risks associated with adhesion-related complications during the consent process.

Modern perspectives in the treatment of chronic anal fissures.

INTRODUCTION: Anal fissures are commonly encountered in routine colorectal practice. Developments in the pharmacological understanding of the internal anal sphincter have resulted in more conservative approaches towards treatment. Simple measures are often effective for early fissures. Glyceryl trinitrate is well established as a first-line pharmacological therapy. The roles of diltiazem and botulinum, particularly as rescue therapy, are not well understood. Surgery has a defined role and should not be discounted completely. METHODS: Data were obtained from Medline publications citing 'anal fissure'. Manual cross-referencing of salient articles was conducted. We have sought to highlight various controversies in the management of anal fissures. FINDINGS: Acute fissures may heal spontaneously, although simple conservative measures are sufficient. Idiopathic chronic anal fissures need careful evaluation to decide what therapy is suitable. Pharmacological agents such as glyceryl trinitrate (GTN), diltiazem and botulinum toxin have been subjected to most scrutiny. Though practices in the UK vary, GTN or diltiazem would be suitable as first-line therapy with botulinum toxin used as rescue treatment. Sphincterotomy is indicated for unhealed fissures; fissurectomy has been revisited and advancement flaps have a role in patients in whom sphincter division is not suitable.