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N J McC Mortensen

Publications and source records attributed to N J McC Mortensen.

At least 19 recordsLinked to original sources
PubMed2007

Histopathological mimicry in mucosal prolapse.

Mucosal prolapse solitary rectal ulcer syndrome is a condition which has frequently confused both pathologists and surgeons alike. Despite its recognition in the nineteenth century, it continues to be a diagnostic challenge. The significance of correctly diagnosing this condition is that it avoids the morbidity and mortality associated with major surgery or the side-effects of long-term medical treatment. This review considers the histological features of mucosal prolapse and how it may mimic other pathological conditions.

Diagnosis, Differential↗
PubMed2006

Long-term follow-up of strictureplasty for Crohn's disease.

BACKGROUND: Strictureplasty is an effective means of alleviating obstructive Crohn's disease while conserving bowel length. The aim of this study was to establish long-term outcomes of strictureplasty. METHODS: Between 1978 and 2003, 479 strictureplasties were performed in 100 patients during 159 operations. Information on Crohn's disease, medical therapy, laboratory indices, surgical details, complication rates and outcomes was recorded. The primary endpoint was abdominal reoperation. RESULTS: Mean follow-up was 85.1 (range 0.2-240.9) months. The overall morbidity rate was 22.6 per cent, with septic complications in 11.3 per cent, obstruction in 4.4 per cent and gastrointestinal haemorrhage in 3.8 per cent. The 30-day mortality rate was 0.6 per cent and the procedure-related series mortality rate 3.0 per cent. Perioperative parenteral nutrition was the only marker for morbidity (P < 0.001). Reoperation rates were 52 per cent at a mean of 40.2 (range 0.2-205.8) months after a first, 56 per cent at 26.1 (range 3.5-63.5) months after a second, 86 per cent at 27.4 (range 1.4-74.5) months after a third, and 62.5 per cent at 25.9 (range 7.3-70.5) months following a fourth strictureplasty procedure. The major risk factor for reoperation was young age (P < 0.001). CONCLUSION: Long-term follow-up has confirmed the safety of strictureplasty in Crohn's disease. Morbidity is appreciable, although the surgical mortality rate is low. Reoperation rates are comparable following first and repeat strictureplasty procedures.

Adolescent↗
PubMed2006

Randomized clinical trial of botulinum toxin plus glyceryl trinitrate vs. botulinum toxin alone for medically resistant chronic anal fissure: overall poor healing rates.

PURPOSE: This study was designed to assess whether addition of glyceryl trinitrate to botulinum toxin improves the healing rate of glyceryl trinitrate-resistant fissures over that achieved with botulinum toxin alone. METHODS: Patients were randomized between botulinum toxin plus glyceryl trinitrate (Group A) and botulinum toxin plus placebo paste (Group B). Patients were seen at baseline, four and eight weeks, and six months. The primary end point was fissure healing at eight weeks. Secondary end points were symptomatic relief, need for surgery, side effects, and reduction in maximum resting and squeeze pressures. RESULTS: Thirty patients were randomized. Two-thirds of patients had maximum anal resting pressures below or within the normal range at entry to the study. Healing rates in both treatment groups were disappointing. There was a nonsignificant trend to better outcomes in Group A compared with Group B in terms of fissure healing (47 vs. 27 percent), symptomatic improvement (87 vs. 67 percent), and resort to surgery (27 vs. 47 percent). CONCLUSIONS: There is some evidence to suggest that combining glyceryl trinitrate with botulinum toxin is superior to the use of botulinum toxin alone for glyceryl trinitrate-resistant anal fissure. The poor healing rate may reflect the fact that many of the patients did not have significant anal spasm at trial entry.

Adult↗
PubMed2005

Cancer surveillance in ulcerative colitis.

BACKGROUND: Patients with ulcerative colitis are at a higher risk of developing colorectal cancer than those without the disease. Surveillance programmes are used routinely to detect dysplasia and cancer in patients with ulcerative colitis. However, such programmes are poorly effective. This article discusses possible improvements suggested by recent research. METHODS: Papers relating to cancer associated with ulcerative colitis and surveillance programmes to detect such cancer were identified using Medline searches. Further papers were identified from the reference lists of identified papers. RESULTS: The probability of cancer for all patients with ulcerative colitis regardless of disease extent was 2 per cent at 10 years, 8 per cent at 20 years and 18 per cent at 30 years; the overall prevalence of colorectal cancer in any patient was 3.7 per cent. Indications for colonoscopic surveillance are extensive disease for 8-10 years, especially in those with active inflammation, a family history of colorectal cancer and primary sclerosing cholangitis. Problems affecting surveillance include the diagnosis of dysplasia, difficulty in differentiating 'sporadic' adenomas from a dysplasia-associated lesion or mass, and decision making based on surveillance findings. Molecular genetic and endoscopic advances to alleviate these problems are discussed. CONCLUSION: Rates of detection of dysplasia can be improved by chromoendoscopy. Molecular genetics has the potential to identify patients most at risk of cancer and can differentiate between different types of lesion.

Aneuploidy↗
PubMed2005

Long-term function after restorative proctocolectomy.

PURPOSE: Early functional outcome after restorative proctocolectomy and formation of an ileoanal pouch is known to be good, but there are minimal data on the long-term function of the pouch. The aim of this study was to look at the long-term functional outcome in patients who had undergone restorative proctocolectomy and formation of an ileoanal pouch. METHODS: A total of 151 consecutive patients (96 males, 55 females) who underwent ileoanal pouch surgery between April 1983 and May 1993 were identified. Functional outcomes from the previous 12 months were appraised by a standardized questionnaire. RESULTS: The median age at surgery was 31 years (range, 6-63 years), with a median follow-up of 142 months (range, 100-221 months). Eighteen patients have had their pouches excised, with another patient being defunctioned. Therefore 19 patients (13 percent) had suffered pouch failure. Altogether, 115 patients were available for follow-up, and 98 patients (85 percent) returned questionnaires. The median pouch-emptying frequency was five times (range, 1-17) during the day and one time (range, 0-6) at night. A total of 74 percent of patients had perfect continence during the day. Most of the patients had no life-style restrictions related to the pouch, and 98 percent of patients would recommend a pouch to others. CONCLUSIONS: Long-term functional outcome after ileoanal pouch surgery is good in most patients. For patients requiring proctocolectomy, ileoanal pouch surgery can now be recommended as an excellent long-term option.

Adolescent↗
PubMed2004

Mechanism of action of botulinum toxin on the internal anal sphincter.

BACKGROUND: Botulinum toxin is an effective treatment for anal fissure. Manometric studies support an apparent action of botulinum toxin on the internal anal sphincter (IAS). This aim of this study was to establish the underlying mechanism. METHODS: Porcine IAS strips were suspended in a superfusion organ bath and allowed to equilibrate. Electrical field stimulation (EFS) was applied with parameters that induced nitrergic relaxation followed by noradrenaline-mediated contraction. These responses were compared before and after addition of botulinum toxin. RESULTS: All strips developed myogenic tone, which was slightly increased following the addition of botulinum toxin. EFS-induced nitrergic relaxation was unaffected by toxin treatment. However, EFS-induced contraction was significantly reduced by toxin treatment. 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP), a nicotinic agonist, caused muscle strip contraction, which was blocked by guanethidine, implying the presence of sympathetic ganglia within the IAS. Botulinum toxin significantly attenuated DMPP-induced contraction. CONCLUSION: In the treatment of anal fissure the major effect of botulinum toxin on the IAS is blockade of sympathetic (noradrenaline mediated) neural output. This is probably a postganglionic action, involving a reduction in noradrenaline release at the neuromuscular junction. Botulinum toxin has no significant effect on nitrergic transmission, which is probably not vesicular in nature.

Anal Canal↗
PubMed2004

Chronic anal fissure.

BACKGROUND: The treatment of chronic anal fissure has shifted in recent years from surgical to medical. METHODS: A Medline search of studies relevant to modern management of chronic anal fissure was undertaken. RESULTS: Traditional surgery that permanently weakens the internal sphincter is associated with a risk of incontinence. Medical therapies temporarily relax the internal sphincter and pose no such danger, but their limited efficacy has led to displacement rather than replacement of traditional surgery. Emerging medical therapies promise continued improvement and new sphincter-sparing surgery may render traditional surgery redundant. CONCLUSION: First-line use of medical therapy cures most chronic anal fissures cheaply and conveniently. The few non-responders can be targeted for sphincter assessment before traditional surgery. If the initial good results of new sphincter-sparing surgery are confirmed, it may be possible to avoid any risk of incontinence, while achieving high rates of fissure healing.

Anal Canal↗
PubMed2004

Perianal Crohn's disease.

BACKGROUND: The management of perianal Crohn's disease is difficult. A wide variety of treatment options exist although few are evidence based. METHODS: A search was conducted using the National Library of Medicine for articles on perianal Crohn's disease and its incidence, classification, assessment and management. RESULTS AND CONCLUSION: Perianal Crohn's disease can manifest as skin tags, ulcers, fissures, abscesses, fistulas or stenoses. Improved radiological imaging with endoanal anal ultrasonography and magnetic resonance imaging has improved its assessment and may be used to predict outcome after surgery. Many treatment options exist. During acute complications they are generally aimed at resolving the immediate problem and limiting damage to anal and perianal tissues; this may be a 'bridge' to definitive treatment. The likelihood of success of definitive treatment must be weighed against the risk of complications, especially faecal incontinence.

Aminosalicylic Acids↗
PubMed2004

Preoperative chemoradiotherapy and total mesorectal excision surgery for locally advanced rectal cancer: correlation with rectal cancer regression grade.

PURPOSE: Preoperative long-course chemoradiotherapy is recommended for rectal carcinoma when there is concern that surgery alone may not be curative. Downstaging of the tumor can be measured as rectal cancer regression grade (1-3) and may be of importance when estimating the prognosis. The aim of this study was to look at the long-term results of tumor regression in patients receiving long-course chemotherapy before surgical resection of rectal cancer. METHODS: We reviewed those patients who received preoperative chemoradiotherapy followed by surgical resection for carcinoma of the mid rectum or distal rectum found to be stage T3/4 between January 1995 and November 1999. Patients received 45 to 50 Gy irradiation in 2-Gy fractions and an infusion of 5-fluorouracil. Surgical specimens were assessed for rectal cancer regression grade. Patients were followed up routinely with clinical examination, computed tomography, and colonoscopy. RESULTS: Sixty-five patients with a mean age 65 (range, 32-83) years underwent chemoradiotherapy before surgical resection. Thirty patients (46 percent) were classified as rectal cancer regression Grade 1, with 9 patients (14 percent) having complete sterilization of the tumor. Fifty-three patients (82 percent) underwent a curative resection. Overall survival, with a median follow-up of 39 (range, 24-83) months, was 67 percent and was associated with tumor downstaging. The local recurrence rate was 5.8 percent in those patients who underwent a curative resection and was significantly lower with rectal cancer regression Grade 1 tumors (P = 0.03). Eight of nine patients (89 percent) whose tumor had been sterilized were alive and well with no recurrence of tumor at a median follow-up of 41 (range, 24-70) months. CONCLUSIONS: Preoperative chemoradiotherapy resulted in significant regression of tumor. Overall survival was high and was associated with downstaging of tumor. The local recurrence rate was significantly lower with rectal cancer regression Grade 1 tumors and was not seen in patients with sterilized tumors.

Adenocarcinoma↗
PubMed2004

Postoperative leakage and abscess formation after colorectal surgery.

Anastomotic leaks following colorectal surgery may be divided into those which are clinically significant and those which are not. Leakage occurs in 3.4-6% of all colorectal cases. It is most commonly associated with rectal anastomoses, being clinically significant in 2.9-15.3% of cases. Mortality following a leak may be 6.0-39.3%. There is no evidence that preoperative bowel preparation reduces the rate and consequences of leaks. There is no evidence for the use of drains when an anastomosis has been made outside the pelvis, but pelvic drainage may be important after anterior resection. The use of covering stomas has not been shown to reduce leak rate but does mitigate the clinical effects of leaks. Prompt diagnosis and further laparotomy can reduce mortality following leakage. Intra-abdominal abscesses can in most cases be treated by radiologically guided drainage. Anastomotic leaks are the most common cause of anastomotic strictures and are also associated with increased rates of local recurrence of cancer.

Abscess↗
PubMed2003

L-Erythro-methoxamine is more potent than phenylephrine in effecting contraction of internal anal sphincter in vitro.

BACKGROUND: Topical phenylephrine has been shown to increase resting anal canal pressure in normal and incontinent individuals. However, high concentrations of gel (10-40 per cent) are required that may cause local side-effects. The aim of this study was to determine whether methoxamine, another alpha-1-adrenoceptor agonist, might be a more potent alternative to phenylephrine. METHODS: Porcine internal anal sphincter (IAS) tissue was cut into strips, suspended in a superfusion organ bath and allowed to equilibrate. Strips were subjected to each drug under test for 20 s, sufficient to obtain stable tone. Phenylephrine, methoxamine (1 : 1 : 1 : 1 ratio of its four isomers) and each of the individual isomers of methoxamine were evaluated in turn. RESULTS: In vitro, methoxamine racemate and phenylephrine were similarly potent in causing contraction of IAS strips (mean(s.e.m.) dose giving half maximal effect (EC(50)) at 74.7(16.5) versus 58.3(13.4) micro M respectively; P = 0.443). However, one of the methoxamine isomers, L-erythro-methoxamine (EC(50) 17.6(3.7) micro M), was significantly more potent than the other three isomers, methoxamine racemate and phenylephrine (P = 0.002). CONCLUSION: L-Erythro-methoxamine is four times more potent than phenylephrine and is a possible treatment for incontinence. Trials are under way to examine the efficacy of L-erythro-methoxamine in vivo.

Adrenergic alpha-Agonists↗
PubMed2003

Options for sphincter preservation in surgery for low rectal cancer.

BACKGROUND: Abdominoperineal excision of the rectum with a permanent end-sigmoid colostomy was the classical operation for cancer of the distal third of the rectum. A number of factors have recently led to a more conservative approach, allowing sphincter preservation when excising tumours that are not invading the anal sphincter. METHODS: The review is based on the published literature of the treatment of low rectal cancers accessed by searching Medline and other online databases. It includes a description of all the surgical options currently available for low rectal tumours, and a discussion of the advantages and disadvantages of the types of anastomosis and reconstruction. RESULTS AND CONCLUSION: It is now technically possible to remove rectal cancer that is extending into the anal canal with preservation of the anal sphincter mechanism and with a satisfactory oncological outcome. Ultra-low colorectal and coloanal anastomosis, together with a colonic pouch or coloplasty, produces acceptable function in many patients. However, there is still controversy about the risk of tumour implantation, the place of downsizing neoadjuvant therapy, and true long-term functional outcome. Despite these concerns, surgeons should strive to perform rectal resection with sphincter preservation for low-lying rectal cancer whenever possible.

Anal Canal↗
PubMed2002

Quantification of histologic regression of rectal cancer after irradiation: a proposal for a modified staging system.

PURPOSE: Long-course preoperative radiotherapy has been recommended for rectal carcinoma when there is concern about the ability to perform a curative resection, for example, in larger tethered tumors or those sited anteriorly or near the anal sphincter. "Downstaging" of the tumor may occur, and this is of importance when estimating the prognosis and selecting postoperative therapy for patients. We studied the effects of preoperative chemoradiotherapy on the pathology of rectal cancer, and we propose a simplified measurement of tumor regression, the Rectal Cancer Regression Grade. METHODS: We have reviewed those patients who received preoperative chemoradiotherapy followed by surgical resection for carcinomas of the mid or distal third of the rectum found to be Stage T3/4 on transrectal ultrasound or CT between January 1995 and December 1998. Patients received 45 to 50 Gy irradiation and an infusion of 5-fluorouracil. The surgical specimens were examined by one pathologist, and the Rectal Cancer Regression Grade was quantified. RESULTS: Forty-two patients, mean age 60 (range, 42-86) years, underwent chemoradiotherapy before surgery for rectal carcinoma. There were 28 anterior resections (67 percent; 9 with a colonic pouch), 12 abdominoperineal resections (27 percent), and 2 Hartmann's procedures (5 percent). Comparison of preoperative and pathologic staging revealed that the depth of invasion was downstaged in 17 patients (38 percent), and the status of involved lymph nodes was downstaged in 13 (50 percent) of 26 patients. Tumor regression was more than 50 percent (Rectal Cancer Regression Grades 1 and 2) in 36 patients (86 percent), with 7 patients (17 percent) having complete regression with absence of residual cancer cells. CONCLUSION: Significant tumor regression was seen in 86 percent of cases after chemoradiotherapy, with 19 patients showing a "good" responsiveness. We propose a modified pathologic staging system for irradiated rectal cancer, the Rectal Cancer Regression Grade, which includes a measurement of tumor regression. The utility of the proposed Rectal Cancer Regression Grade must be tested against long-term outcomes before its value in predicting prognosis and survival can be determined.

Adult↗
PubMed2002

Evidence for separate disease phenotypes in intestinal Crohn's disease.

BACKGROUND: This study investigated the hypothesis that separate phenotypes of Crohn's disease exist which display differing patterns of recurrence with a tendency to preservation of phenotype between serial operations. METHODS: Some 483 abdominal operations (278 patients) were identified from a prospectively compiled database. Patterns of recurrence (reoperation) were analysed by Kaplan-Meier plots and log rank tests according to disease phenotype (perforated, stenosed or ulcerated). Serial operations were analysed by agreement of phenotype and microscopic features of disease using kappa statistics and correlation coefficients. RESULTS: There was no significant difference in recurrence according to disease phenotype (median reoperation-free survival time 43.0, 50.2 and 47.9 months for perforated, stenosed and ulcerated types respectively; log rank chi(2) = 3.5, P = 0.18). There was poor agreement in phenotype between serial operations (kappa = 0.22 for first/second operation and kappa= 0.15 for second/third operation) and no significant correlation between pathological features was identified (r between -0.19 and 0.48). CONCLUSION: No evidence was found for the existence of separate disease phenotypes with differing natural histories or underlying pathological characteristics.

Crohn Disease↗
PubMed2002

An insight into the genetic pathway of adenocarcinoma of the small intestine.

BACKGROUND: Although the adenoma to carcinoma pathway in colorectal cancer is well described, the mechanisms of carcinogenesis in the small intestine remain unclear. AIMS: The aim of this study was to investigate candidate genes in the genetic pathway of adenocarcinoma of the small intestine. SUBJECTS AND METHODS: A total of 21 non-familial, non-ampullary adenocarcinomas of the small intestine were analysed. DNA was extracted from formalin fixed paraffin wax embedded tissue using standard techniques. The replication error (RER) status was determined by amplification of BAT26. The mutation cluster region (MCR) of the adenomatous polyposis coli (APC) gene was screened using polymerase chain reaction single strand conformational polymorphism and direct sequencing. Immunohistochemistry was performed on formalin fixed paraffin wax embedded tissue using monoclonal antibodies for hMLH1, hMSH2, beta-catenin, E-cadherin, and p53. RESULTS: Fourteen male and seven female patients with a median age of 64 years (range 21-85) presented with adenocarcinoma of the duodenum (10), jejunum (7), and ileum (4). One cancer (5%) was found to be RER+, and all tumours stained positive for hMLH1 and hMSH2. No mutations were detected in the MCR of the APC gene. beta-Catenin showed increased nuclear expression with loss of membranous staining in 10 cancers (48%). Absent or decreased membrane expression of E-cadherin was found in eight cancers (38%). Strong staining of p53 was found in the nucleus of five cancers (24%). CONCLUSION: We did not detect mutations in the MCR of the APC gene, and this suggests that adenocarcinoma of the small intestine may follow a different genetic pathway to colorectal cancer. Abnormal expression of E-cadherin and beta-catenin was common and reflects an early alternative to APC in this pathway in which mutations may be found in adenocarcinoma of the small intestine.

Adaptor Proteins, Signal Transducing↗