A Maximum Entropy Resolution to the Wine/Water Paradox

The Principle of Indifference ('PI': the simplest non-informative prior in Bayesian probability) has been shown to lead to paradoxes since Bertrand (1889). Von Mises (1928) introduced the 'Wine/Water Paradox' as a resonant example of a 'Bertrand paradox', which has been presented as demonstrating that the PI must be rejected. We now resolve these paradoxes using a Maximum Entropy (MaxEnt) treatment of the PI that also includes information provided by Benford's 'Law of Anomalous Numbers' (1938). We show that the PI should be understood to represent a family of informationally identical MaxEnt solutions, each solution being identified with its own explicitly justified boundary condition. In particular, our solution to the Wine/Water Paradox exploits Benford's Law to construct a non-uniform distribution representing the universal constraint of scale invariance, which is a physical consequence of the Second Law of Thermodynamics.

Relating a System's Hamiltonian to Its Entropy Production Using a Complex Time Approach

We exploit the properties of complex time to obtain an analytical relationship based on considerations of causality between the two Noether-conserved quantities of a system: its Hamiltonian and its entropy production. In natural units, when complexified, the one is simply the Wick-rotated complex conjugate of the other. A Hilbert transform relation is constructed in the formalism of quantitative geometrical thermodynamics, which enables system irreversibility to be handled analytically within a framework that unifies both the microscopic and macroscopic scales, and which also unifies the treatment of both reversibility and irreversibility as complementary parts of a single physical description. In particular, the thermodynamics of two unitary entities are considered: the alpha particle, which is absolutely stable (that is, trivially reversible with zero entropy production), and a black hole whose unconditional irreversibility is characterized by a non-zero entropy production, for which we show an alternate derivation, confirming our previous one. The thermodynamics of a canonical decaying harmonic oscillator are also considered. In this treatment, the complexification of time also enables a meaningful physical interpretation of both "imaginary time" and "imaginary energy".

Adhesion-related readmissions after open and laparoscopic surgery: a retrospective cohort study (SCAR update)

BACKGROUND

Adhesions are the most common driver of long-term morbidity after abdominal surgery. Although laparoscopy can reduce adhesion formation, the effect of minimally invasive surgery on long-term adhesion-related morbidity remains unknown. We aimed to assess the impact of laparoscopy on adhesion-related readmissions in a population-based cohort.

METHODS

We did a retrospective cohort study of patients of any age who had abdominal or pelvic surgery done using laparoscopic or open approaches between June 1, 2009, and June 30, 2011, using validated population data from the Scottish National Health Service. All patients who had surgery were followed up until Dec 31, 2017. The primary outcome measure was the incidence of hospital readmissions directly related to adhesions in the laparoscopic and open surgery cohorts at 5 years. Readmissions were categorised as directly related to adhesions, possibly related to adhesions, and readmissions for an operation that was potentially complicated by adhesions. We did subgroup analyses of readmissions by anatomical site of surgery and used Kaplan-Meier analyses to assess differences in survival across subgroups. We used multivariable Cox-regression analysis to determine whether surgical approach was an independent and significant risk factor for adhesion-related readmissions.

FINDINGS

Between June 1, 2009, and June 30, 2011, 72 270 patients had an index abdominal or pelvic surgery, of whom 21 519 (29·8%) had laparoscopic index surgery and 50 751 (70·2%) had open surgery. Of the 72 270 patients who had surgery, 2527 patients (3·5%) were readmitted within 5 years of surgery for disorders directly related to adhesions, 12 687 (17·6%) for disorders possibly related to adhesions, and 9436 (13·1%) for operations potentially complicated by adhesions. Of the 21 519 patients who had laparoscopic surgery, 359 (1·7% [95% CI 1·5-1·9]) were readmitted for disorders directly related to adhesions compared with 2168 (4·3% [4·1-4·5]) of 50 751 patients in the open surgery cohort (p<0·0001). 3443 (16·0% [15·6-16·4]) of 21 519 patients in the laparoscopic surgery cohort were readmitted for disorders possibly related to adhesions compared with 9244 (18·2% [17·8-18·6]) of 50 751 patients in the open surgery cohort (p<0·005). In multivariate analyses, laparoscopy reduced the risk of directly related readmissions by 32% (hazard ratio [HR] 0·68, 95% CI 0·60-0·77), and of possibly related readmissions by 11% (HR 0·89, 0·85-0·94) compared with open surgery. Procedure type, malignancy, sex, and age were also independently associated with risk of adhesion-related readmissions.

INTERPRETATION

Laparoscopic surgery reduces the incidence of adhesion-related readmissions. However, the overall burden of readmissions associated with adhesions remains high. With further increases in the use of laparoscopic surgery expected in the future, the effect at the population level might become larger. Further steps remain necessary to reduce the incidence of adhesion-related postsurgical complications.

FUNDING

Dutch Adhesion Group and Nordic Pharma.

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.

The outcome of self-expanding metal stents in elderly patients

Background and Objectives:

Emergency surgery for large bowel obstruction is associated with high morbidity and mortality rates, especially in elderly patients. Colonic self-expanding metal stents may provide temporary relief of obstructions and enable preoperative evaluation. The aim of this retrospective study was to assess the clinical outcomes of emergency stenting in elderly patients with large bowel obstructions.

Methods:

Between 1997 and 2010, patients presenting with large bowel obstructions were treated predominantly with self-expanding metal stent insertion. Clinical data, including age, site of obstruction, success rate, and surgery and mortality rates, were collected. Patients were divided into 3 groups (I, II, and III) according to age: <69, 70 to 79, or >80 years.

Results:

One hundred thirty-two consecutive patients underwent stent implantation, with a mean age of 72.1 years (range, 28–95 years). Similar diversity of sex, indication, and stricture location was found. There were no significant differences in clinical success (88.7%, 73.8%, and 78.4%, P = .16) and stent-related mortality (2.1%, 3.3%, and 3.6%, P = 1.00). Similar rates of stoma creation were also found (59.3%, 46.7%, and 60.0%, P = .76). In contrast, rates of surgery were lower in older patients (50.9%, 38.1%, and 13.5%, P = .0013), and mortality during the same admission was significantly higher in patients >70 years of age (4.0%, 15.0%, and 22.2%, P = .027). Kaplan-Meier 30-day survival curves for the 3 groups showed a trend toward earlier death among patients >70 years of age.

Conclusions:

This study demonstrates that stenting provides similar success rates in all age groups but is associated with higher mortality rates in older patients.

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).

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.

Management of asymptomatic inguinal hernia: a systematic review of the evidence

OBJECTIVE

To establish a literature-based surgical approach to asymptomatic inguinal hernia (IH).

DATA SOURCES

PubMed, the Cochrane Library database, Embase, national guidelines (including the National Library of Guidelines Specialist Library), National Institute for Health and Clinical Excellence guidelines, and the National Research Register were searched for prospective randomized trials comparing surgical treatment of patients with asymptomatic IH with conservative treatment.

STUDY SELECTION

The literature search retrieved 216 article headlines, and these articles were analyzed. Of those studies, a total of 41 articles were found to be relevant and 2 large well-conducted randomized controlled studies that published their results in several articles were reviewed.

DATA EXTRACTION

The pain and discomfort, general health status, complications, and life-threatening events of patients with asymptomatic IH managed by surgery or watchful waiting were determined.

DATA SYNTHESIS

No significant difference in pain scores and general health status were found when comparing the patients who were followed up with the patients who had surgery. A significant crossover ratio ranging between 23% and 72% from watchful waiting to surgery was found. In patients with watchful waiting, the rates of IH strangulation were 0.27% after 2 years of follow-up and 0.55% after 4 years of follow-up. In patients who underwent elective surgery, the range of operative complications was 0% to 22.3% and the recurrence rate was 2.1%.

CONCLUSION

Both treatment options for asymptomatic IH are safe, but most patients will develop symptoms (mainly pain) over time and will require operation.

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.

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.

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.

Adhesions after abdominal surgery in children

PURPOSE

The objective of this study is to quantify the overall burden (operative and nonoperative) of small bowel obstruction caused by adhesions after laparotomy in children.

METHODS

Data from the Scottish National Health Service Medical Record Linkage database were used to assess risk of an adhesion-related readmission in the 5 years after open abdominal surgery in children and adolescents younger than 16 years from April 1996 to March 1997.

RESULTS

A total of 1581 children underwent abdominal surgery (ie, from duodenum downward). Patients undergoing surgery on the ileum had the highest risk of readmission because of adhesions in the subsequent 5 years after surgery (9.2%)--formation/closure of ileostomy had the greatest risk (25%); 6.5% of children were readmitted after general laparotomy, 4.7% after duodenal surgery, and 2.1% after colonic surgery. The incidence of readmissions was 0.3% after appendicectomy. The overall readmission rate was 5.3% (if appendicectomy was excluded) and 1.1% (if appendicectomy was included).

CONCLUSION

This population-based study has demonstrated that children have a high incidence of readmissions owing to adhesions after lower abdominal surgery. The risks are related to the site and the type of the original surgery. The risk of further readmissions was highest in the first year but continued with time. The data enable surgeons to target antiadhesion strategies at procedures that lead to a high risk of adhesions.

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.

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.

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.

Indwelling trans-anastomotic rectal tubes in colorectal surgery: a survey of usage in UK and Ireland

BACKGROUND

The use of rectal tubes in colorectal surgery appears to be a matter of individual choice, with little documented evidence to support their use. This study assesses the current practice of rectal tubes amongst consultant members of the Association of Coloproctology of Great Britain & Ireland (ACPGBI).

METHODS

A piloted questionnaire was sent to practising ACPGBI consultant members listed in the 2003-04 directory. Statistical analysis was performed using SPSS software and Fishers exact test.

RESULTS

Three hundred and thirty-nine replies were received from 579 posted questionnaires (response rate = 58.5%). Rectal tubes were used by 116 (35%) of responding surgeons. Rectal tubes were more commonly used by surgeons with less than 10 years practice as a consultant (P < 0.005). The main indications for tube placement were following ileo-anal or colonic pouch surgery (73%), after any anterior resection (36%) (rectal tubes were reserved for only low anterior resections by 16% of surgeons) and in the rectal stump after total or subtotal colectomy for acute colitis (11%). Twenty-three percent of these practising surgeons would use a rectal tube as an alternative to a diverting stoma, predominantly in selected patients following ileo-anal pouch surgery. A Foley catheter was the commonest type of tube used (70%) and this was usually placed above the anastomosis (80%). Rectal tubes were left in situ for a median of 5 days (range = 1-13 days). Three surgeons (2.6%) reported serious complications including tube perforation of the bowel or anastomosis. Several different mechanisms were suggested for the purpose and functioning of the rectal tube, the commonest being to decompress the rectum and/or pouch.

CONCLUSION

Rectal tube placement is simple and safe and is used by a third of colorectal surgeons in UK and Ireland. Given their simplicity, the efficacy of rectal tubes in reducing local anastomotic complications requires further evaluation within the confines of a randomised controlled trial.

Colorectal stenting

Increasing in popularity

Population-based analysis of the risk of adhesion-related readmissions after abdominal surgery in children

PURPOSE

The aim of this study was to quantify the risk of adhesion-related readmissions after abdominal surgery in children.

METHODS

This was a population-based study. One thousand five hundred eighty-one children younger than 16 years underwent laparotomy in 1996. Patients were identified from the Scottish Morbidity Records database and followed up for 4 years.

RESULTS

In children younger than 5 years, 4.2% had a readmission "directly" owing to adhesions. In children younger than 16 years, 1.1% had a readmission directly owing to adhesions. The highest risk of readmission followed surgery on the small intestine (9.3%), followed by abdominal wall surgery (5.8%), duodenal surgery (2.6%), colonic surgery (2.1%), and appendicectomy (0.3%). 55% of all readmissions occurred in the first year.

CONCLUSION

There was no difference in readmission rates between younger and older children when comparing the organ on which surgery was initially performed. The highest readmission rate followed small intestinal surgery and the lowest followed appendicectomy. The risk of readmission was highest in the first year.

Endoscopic alternatives in managing anastomotic strictures of the colon and rectum

BACKGROUND

The development of anastomotic strictures following colorectal surgery is a frequent problem, but commonly used treatments (e.g. dilatation or revisional surgery) are often ineffective. This study assessed the efficacy of self-expanding metallic stents (SEMS) and endoscopic transanal resection of strictures (ETARS) in managing high-grade benign colorectal anastomotic strictures after the failure of first-line therapies.

METHODS

All patients with biopsy-proven benign anastomotic strictures (luminal diameter<7 mm) following colorectal surgery, seen in the period April 1995-October 2004, were treated with either SEMS or ETARS.

RESULTS

In the study period, we treated 10 patients (7 men) of median age 71 years. Ten ETARS procedures were performed in six patients, with a mean operating time of 42 minutes and a median hospital stay of 1 day. Early complications of ETARS included: re- operation for bleeding, asymptomatic anastomotic perforation and technical failure in an acutely angulated stricture. SEMS were successfully inserted into five patients (including two with failed ETARS) without any early complications. Overall, nine patients have had satisfactory longterm outcomes (median follow-up, 29 months; range, 3-75 months).

CONCLUSIONS

SEMS and ETARS are simple, safe and effective methods in treating high-grade anastomotic strictures.

Self-expanding metallic stents in the treatment of benign colorectal disease: indications and outcomes

OBJECTIVE

The use of stents for benign colorectal obstruction is considered controversial because of a lack of data and perceived high failure and complication rates. The aim of this study was to evaluate the indications and outcomes following stent placement for benign colorectal disease in a UK district general hospital and to review the published literature.

PATIENTS AND METHODS

Between 1997 and 2004, 11 of 90 attempted stent insertions were performed for benign colorectal disease (diverticular disease, 4; anastomotic strictures, 4; idiopathic rectal stricture, 1; rectal endometriosis, 1; caecal volvulus, 1). Complications and outcomes were analysed from a prospective database.

RESULTS

Stent insertion was successful in nine patients. Early complications occurred in two patients (both with diverticular disease): one patient failed to decompress and needed a colostomy and laparotomy was performed in a second patient who developed peritonitis after five days although no stent perforation of the bowel was identified. Two patients were successfully decompressed and underwent subsequent elective surgery with full bowel preparation. Stent placement resulted in symptomatic improvement in three out of four patients with anastomotic strictures (allowing closure of defunctioning stomas) and in the one patient with an idiopathic rectal stricture. Stent migration occurred in two of these patients without recurrence of symptoms. Stent fracture occurred in one patient, who remained symptomatic.

CONCLUSIONS

Self-expanding metallic stents are an effective treatment for benign colorectal obstructions, especially anastomotic strictures with long-term patency. Stents should be avoided in acute diverticular disease because of a higher incidence of complications.

The SCAR-3 study: 5-year adhesion-related readmission risk following lower abdominal surgical procedures

OBJECTIVE

The Surgical and Clinical Adhesions Research (SCAR) and SCAR-2 studies demonstrated that the burden of adhesions following lower abdominal surgery is considerable and appears to remain unchanged despite advances in strategies to prevent adhesions. In this study, we assessed the adhesion-related readmission risk directly associated with common lower abdominal surgical procedures, taking into account the effect of previous surgery, demography and concomitant disease.

METHODS

Data from the Scottish National Health Service medical record linkage database were used to assess the risk of an adhesion-related readmission following open lower abdominal surgery during April 1996-March 1997.

RESULTS

Patients undergoing lower abdominal surgery (excluding appendicectomy) had a 5% risk of readmission directly related to adhesions in the 5 years following surgery. Appendicectomy was associated with a lower rate of readmission (0.9%), but contributed over 7% of the total lower abdominal surgery patient readmission burden. Panproctocolectomy (15.4%), total colectomy (8.8%) and ileostomy surgery (10.6%) were associated with the highest risk of an adhesion-related readmission. Overall, the risk of readmission was doubled in patients who had undergone abdominal or pelvic surgery within 5 years of the incident operation. A higher risk of readmission was also recorded in patients aged < 60 years compared with those aged > or = 60 yrs. The effect of gender was assessed. However, as the surgical codes used were found to be skewed towards women, these data have not been reported. Readmission risk was slightly higher in patients with concomitant peritonitis compared with patients without peritonitis. In contrast, Crohn's disease had no effect on risk. Patients with colorectal cancer had a lower risk of adhesion formation. However, this may have been due to the type of surgery performed in this patient group.

CONCLUSION

The identification of high-risk patient subgroups may assist in effectively targeting adhesion-prevention strategies and the proffering of preoperative advice on adhesion risk.

Colovesical fistula--is a surgical approach always justified?

OBJECTIVE

There is a tendency to over investigate patients with colovesical fistula and to advise surgical intervention as the sole course of action. Most patients are elderly and operative intervention often carries a high morbidity and mortality.

PATIENTS AND METHODS

A retrospective study of 50 patients diagnosed with a colovesical fistula over a 12-year period was undertaken at our institution. The notes of all these patients were reviewed using a standardized proforma to look at the referral pattern, symtomatology, investigation, treatment and outcomes.

RESULTS

Data analysis showed the median age of these patients to be 70 years with 92% having either pneumaturia or faecaluria or both as a symptom. There was no significant difference in disease-specific mortality in patients with benign colovesical fistula undergoing surgical intervention and patients treated conservatively. There was not a single documented case of septicaemia despite untreated colovesical fistula being present for a cumulative total of 3254 weeks. There was no statistically significant decline in the renal function due to the disease.

CONCLUSION

We suggest that fewer investigations be performed for the diagnosis of colovesical fistula and conservative management offered to patients with benign pathology.

Immobilisation of vaccines onto micro-crystals for enhanced thermal stability

The thermal instability of many vaccines leads to the wastage of half of all supplied vaccines. In this note, we report the application of a novel technology: protein-coated micro-crystals (PCMC) to improve the thermostability of a model vaccine (diphtheria toxoid, DT). The latter was immobilised onto the surface of a crystalline material (L-glutamine) via a rapid dehydration method, resulting in the production of a fine free-flowing powder. The PCMC consisted of thin, flat crystals with an antigen loading of 3.95% (w/w). The DT-coated glutamine crystals and free DT (the controls) were incubated at different temperatures for a defined time period (4 degrees C, RT and 37 degrees C for 2 weeks and 45 degrees C for 2 days), after which the crystals were suspended in buffer and intramuscularly administered to mice. Incubation of DT (free and crystal-coated) at room temperature and at 37 degrees C for 2 weeks did not result in any change in the antibody response compared to DT that had always been stored properly (i.e. in the refrigerator). In contrast, incubation of free DT at 45 degrees C resulted in a reduced IgG response, indicating thermal instability of free DT at that temperature. The antibody response was not reduced, however, with the crystal-coated DT. These preliminary studies show that PCMC is a promising technology for the thermal stabilisation of vaccines.

Long-term survival from gastrocolic fistula secondary to adenocarcinoma of the transverse colon

Background

Gastrocolic fistula is a rare presentation of both benign and malignant diseases of the gastrointestinal tract. Malignant gastrocolic fistula is most commonly associated with adenocarcinoma of the transverse colon in the Western World. Despite radical approaches to treatment, long-term survival is rarely documented.

Case presentation

We report a case of a 24-year-old woman who presented with the classic triad of symptoms associated with gastrocolic fistula. Radical en-bloc surgery and adjuvant chemotherapy were performed. She is still alive ten years after treatment.

Conclusions

Gastrocolic fistula is an uncommon presentation of adenocarcinoma of the transverse colon. Radical en-bloc surgery with adjuvant chemotherapy may occasionally produce long-term survival.

The use of the Deaver retractor to visualize staple line haemorrhage following stapled anopexy

Postoperative haemorrhage is a recognized complication of any haemorrhoidectomy procedure. It can be difficult to visualize a staple line haemorrhage in the presence of large circumferential haemorrhoids. We describe a technique to aid visualization of the staple line in this situation.

Colorectal surgery: the risk and burden of adhesion-related complications

OBJECTIVES

Adhesions are associated with serious medical complications. This study examines the real-time burden of adhesion-related readmissions following colorectal surgery and assesses the impact of previous surgery on adhesion-related outcomes.

PATIENTS AND METHODS

The study used data from the Scottish National Health Service Medical Record Linkage Database to identify three cohorts of patients who had undergone open colorectal surgery during the financial years 1996-97, 1997-98 and 1998-99. Each cohort was followed up for at least 2 years and the number and category of adhesion-related readmissions was recorded. The influence of any previous operations on adhesion-related readmissions was also determined by performing a subanalysis within the 1996-97 cohort of patients who had no record of abdominal surgery within either the previous 5 or 15 years. The relative risk of adhesion-related readmissions was also assessed.

RESULTS

In the 1996-97 cohort, 9.0% of patients were readmitted within a year after surgery; 2.1% had complications directly related to adhesions and 6.9% had complications that were possibly related. After 4 years, 19.0% of patients were readmitted for reasons directly or possibly related to adhesions. Many patients were readmitted on more than one occasion and the relative risk of adhesion-related complications was 29.7 per 100 initial procedures over 4 years. In the subgroups that had no record of abdominal surgery within the previous 5 or 15 years, the relative risks of adhesion-related complications were 24.8% and 23.5%, respectively. There was no change in the rate of adhesion-related readmissions following colorectal surgery between 1996 and 1999.

CONCLUSION

Colorectal surgery is associated with a considerable rate of adhesion-related readmissions. Preventative measures should be considered to reduce this risk.

Epidemiology of adhesions: the burden

Until recently the epidemiology of adhesion-related disease was unclear and lack of awareness of the clinical impact and extent of the problem has been cited as the greatest impediment to reducing adhesion formation. The clinical consequences and burden of disease are reviewed.

Pseudomyxoma extraperitonei occurring 35 years after appendicectomy: a case report and review of literature

Background

Pseudomyxoma peritonei is a rare condition consisting of mucinous ascites, most commonly arising from mucinous tumors of the appendix and occasionally from the ovary. Very rarely mucinous implants arise in the retroperitoneum without any intra-peritoneal involvement. This has been termed as pseudomyxoma extraperitonei.

Case presentation

We report a case of a 57 year old man who developed pseudomyxoma extraperitonei, 35 years after undergoing an appendicectomy for a perforated appendix.

Conclusions

Pseudomyxoma extraperitonei has been previously reported, however we report the longest incubation period of 35 years for this condition.

Zoned microstructure fiber for low-dispersion waveguiding and coupling to photonic crystals

We describe a zoned microstructure fiber that exhibits low dispersion and virtually zero spherical aberration because of its optimized piecewise Gaussian index profile. We present results of a nine-zone design that has an average refractive index of 2.3, a refractive-index contrast of 0.1, a first zone radius of 1.67 microm, and a maximum core radius of 5 microm. It has an in-fiber focal length of 8.88 microm and can focus light to a spot size of radius 315 nm, facilitating efficient coupling between single-mode fiber and photonic crystals.

Palliative therapy of colorectal carcinoma: stent or surgery?

"Surgical" palliation of obstructing colorectal carcinomas may involve resection with or without stoma formation, formation of a stoma alone, a colonic bypass procedure, or no procedure at all. Palliative surgical procedures confer a significant morbidity and mortality. Factors associated with increased mortality for colorectal cancer include advancing age of patient, advancing stage of the disease and the necessity for an emergency procedure. Advanced obstructing malignant lesions pose a clinical dilemma as the risks and time of recovery from surgery have to be balanced against providing a dignified quality of remaining life. Self expanding metal stents (SEMS) for acutely obstructing advanced colorectal carcinomas provide a cost effective option that avoids surgery in a usually frail group of patients. They can be inserted under sedation, rapidly decompress the colon and lead to an early return of colonic function. The procedure is carried out endoscopically with radiological assistance to determine a lumen and to confirm adequate stent placement. SEMS are not suitable for low rectal lesions and are more difficult to place in those that traverse colonic flexures. Complications from successful SEMS placement include migration and stent occlusion. The morbidity associated with SEMS is associated with migration or perforation of the colon during placement, pain and less commonly haemorrhage. Despite these problems most patients can be successfully decompressed without further endoscopic or surgical reintervention and allow satisfactory palliation.

A novel method of demonstrating rectal prolapse

BACKGROUND

Full thickness rectal prolapse may be difficult to view in the outpatient setting. We present a novel method to demonstrate it using equipment commonly found in the Urology clinic.