Two experiments examined the effect of pharmacological stimulation of the locus coeruleus in a non-reversal shift paradigm to test predictions concerning the role of the ceruleo-cortical noradrenergic system in processes of selective attention. Food-deprived rats were trained to make either visual (experiment 1) or spatial (experiment 2) discriminations in a parallel alley with both sets of cues being present at all times. Two groups of rats received treatments of either 2 mg/kg i.p. of the selective α(2) adrenoceptor antagonist idazoxan or saline control injections before each daily block of trials. Following attainment of criterion, the reinforcement contingencies were altered according to a non-reversal shift design, so that the alternative (i.e. either spatial or visual) set of cues now predicted reward. Rats treated with idazoxan were not impaired in the acquisition of either the spatial or visual discrimination task, but they were impaired in both forms of non-reversal shift. These deficits are interpreted as resulting from narrowed attention in idazoxan-treated rats, thus supporting a selective attention hypothesis of locus coeruleus function.

The combination of antegrade irrigation via a colonic conduit or an antegrade continence enema procedure provides a successful outcome for some patients when incorporated into total anorectal reconstruction, provided that sepsis does not occur, thus avoiding permanent stoma formation. The combination of these procedures may represent an improvement in total anorectal reconstruction and warrants further clinical trial.

Since setting up a CDU, a successful outcome has been achieved in 33 (70%) of 47 patients undergoing ESGN surgery, which represents a significant improvement over time. This is probably related to improved patient assessment and selection, more reliable equipment and increased operative and peri-operative experience that come with a multidisciplinary team approach.

SirWe commend the authors for their objectivity. Infection, migration and erosion are well-documented serious complications of artificial anal sphincter implantation, yet may be relatively under-reported. It has long been our belief that any artificial devices or material brought into direct contact and completely encircling the bowel wall would eventually fail as a result of displacement and/or subsequent erosion. In this long-term study over three-quarters of the patients experienced postoperative complications and nearly a third had to have definitive explantation of the device. Similar complications led to the failure and subsequent abandonment of the Angelchik prosthesis for gastro-oesophageal reflux disease 1 . In the light of the evidence in this study, we feel that the electrically stimulated gracilis neoanal sphincter perhaps offers a more suitable alternative than the artificial bowel sphincter for the treatment of severe end-stage faecal incontinence, since it utilises autologous tissue 2 . Whilst it appears a more complex procedure, with advances in technology and appropriate training it can now be performed with greater consistency and lower morbidity than during its initial development. Results from our centre show a significant decrease in sepsis and mechanical failure and an overall success rate of approximately 70 per cent in the longer-term. This improvement has been considerably aided by developing a supra-regionally funded multidisciplinary team with reasonable throughput. Whilst we reserve judgement on the artificial bowel sphincter, we suspect that with longer follow-up, like the Angelchik prosthesis, it will be confined to the annals of surgical history.J SirSeow Choen is right to point out that poor surgical performance should not be allowed to hide behind a mask of adjuvant radiotherapy. But there is more than a hint of surgical arrogance in his suggestion that master surgeons only need to do a good operation to ensure a favourable cancer outcome. Sure, there is a minority of surgeons with high local recurrence rates who should be discouraged from continuing to practice on these challenging patients. On the other hand there are probably not enough master surgeons, however defined, to operate on the 9000 new cases of rectal cancer in the United Kingdom each year. There will always be a range of ability; most of us will be around the mean and the aim must be to drive down the average local recurrence rate, by whatever means. This will of course include tutelage under a specialist teacher, but at what point does the newly appointed consultant surgeon become expert? It may take 5-10 years for mature data on local recurrence to become available and it will then be too late for some patients. The master surgeon will still be challenged by the anterior lower rectal third tumour with a whisp of mesorectum separating if from the prostate and an MRI scan predicting tumour within 1mm of the radial margin. More trials are needed to define neo-adjuvant treatment protocols but there is already some e...

Construction of a CCC is a useful technique for the majority of patients with severe evacuatory disorders following the formation of an electrically stimulated gracilis neoanal sphincter, for whom the only alternative would be an end stoma. A CCC may be incorporated with construction of an electrically stimulated gracilis neoanal sphincter in patients at significant risk of postoperative severe evacuatory disorders.