Enhancing bowel screening: Preventing colorectal cancer by flexible sigmoidoscopy in New Zealand.

OBJECTIVES: The prevention of colorectal cancer (CRC) attainable from introducing once-in-a-lifetime flexible sigmoidoscopy (FSIG) screening was assessed. STUDY DESIGN: This is a review of relevant available information for the assessment of the impact and resource demands of FSIG in New Zealand. METHODS: The reduction in bowel cancer incidence achievable by one-off FSIG screening from 50 to 59 years of age, an age group for which bowel screening is not currently offered, was reviewed. The prevention of CRC attainable from an offer of screening at 55 years of age in New Zealand was also estimated. The number and cost of the FSIG screening procedures required and referrals for colonoscopies and the savings in treatment were calculated. RESULTS: Annually, about 27,500 FSIG screening procedures would be required if 50% of those turning 55 years of age accepted an offer of once-in-a-lifetime FSIG screening. This would result in three-four-fold fewer people being referred for colonoscopy than in the national 2-yearly faecal immunochemical test (FIT) screening programme and subsequently reduce demand for colonoscopy from a false-positive FIT. The number of CRC cases prevented would increase over 17 years to more than 300 per year by 2033. After 10-15 years of screening, the annual savings in health service costs, primarily from CRC prevented, were sufficient to completely fund the FSIG screening. CONCLUSIONS: Inclusion of FSIG screening in the national bowel screening programme would significantly reduce both the incidence and mortality of CRC in New Zealand, reduce the colonoscopy demand of current bowel screening and reduce long-term health service costs.

Australasian Laparoscopic Colon Cancer Study shows that elderly patients may benefit from lower postoperative complication rates following laparoscopic versus open resection.

BACKGROUND: A retrospective analysis of age-related postoperative morbidity in the Australia and New Zealand prospective randomized controlled trial comparing laparoscopic and open resection for right- and left-sided colonic cancer is presented. METHODS: A total of 592 eligible patients were entered and studied from 1998 to 2005. RESULTS: Data from 294 patients who underwent laparoscopic and 298 who had open colonic resection were analysed; 266 patients were aged less than 70 years and 326 were 70 years or older (mean(s.d.) 70.3(11.0) years). Forty-three laparoscopic operations (14.6 per cent) were converted to an open procedure. Fewer complications were reported for intention-to-treat laparoscopic resections compared with open procedures (P = 0.002), owing primarily to a lower rate in patients aged 70 years or more (P = 0.002). Fewer patients in the laparoscopic group experienced any complication (P = 0.035), especially patients aged 70 years or above (P = 0.019). CONCLUSION: Treatment choices for colonic cancer depend principally upon disease-free survival; however, patients aged 70 years or over should have rigorous preoperative investigation to avoid conversion and should be considered for laparoscopic colonic resection. REGISTRATION NUMBER: NCT00202111 (http://www.clinicaltrials.gov).

The utility of laparoscopy in the diagnosis of acute appendicitis in women of reproductive age.

AIM: To see whether laparoscopy improves the accuracy of a clinical diagnosis of acute appendicitis in women of reproductive age, and to determine what the long-term sequelae are of not removing an appendix deemed at laparoscopy to be normal. METHOD: The initial part of the study was undertaken during 1991-1992. Female patients between 16 and 45 years were eligible for inclusion once a clinical decision had been made to perform an appendicectomy for suspected acute appendicitis. Following consent, patients were randomized into two groups. One group had open appendicectomy, as planned. The other group had laparoscopy, followed by open appendicectomy only if the appendix was seen to be inflamed or was not visualized. The end points for the study were the clinical outcomes of all patients, and the results of histology, where appropriate. An attempt was made to contact all patients at 10 years to determine whether they had had a subsequent appendicectomy, or had been diagnosed with another abdominal condition that might be relevant to the initial presentation in 1991-1992. RESULTS: Laparoscopic assessment was correct in all cases in which the appendix was visualized. Diagnostic accuracy was improved from 75% to 97%. Laparoscopy was associated with no added complications, no increase in hospital stay in patients who went on to appendicectomy, and a reduction in hospital stay for those who underwent laparoscopy alone. No patients developed a problem over the 10-year follow-up period from having a normal-looking appendix not removed at laparoscopy. CONCLUSION: Laparoscopic assessment of the appendix is reliable, and to leave a normal-looking appendix at laparoscopy does not appear to cause any long-term problems.

Follow-up after attempted curative surgery for colorectal cancer; postal survey of New Zealand surgeons' practice.

AIMS: The role of follow-up after attempted curative resection of colorectal cancer (CRC) is not clearly defined. We wished to establish the frequency, duration and type of follow-up practised by New Zealand surgeons. METHODS: A postal survey was performed of surgeons on the General Medical Register, asking about the follow-up of asymptomatic patients after potential curative surgery. RESULTS: The response rate was 66%(107/163). There was wide variability in the frequency, duration and type of the indicated follow-up practice. 97% of surgeons followed their patients on average four monthly for the first year. At five years, 79% of surgeons followed their patients. Routine blood tests were performed 54%, while serum carcinoembryonic antigen (CEA) levels were measured by 56% of surgeons for the first two years. 41% performed abdominal imaging in the first two years. 97% of surgeons screened the remaining colon (88% by colonoscopy). 90% performed colonic screening three to five yearly. CONCLUSIONS: Follow-up after potential curative surgery for CRC appears to be widely practised in New Zealand. There is, however, considerable variation between surgeons in the frequency, duration and type of follow-up. This may reflect the conflicting evidence in the literature on the value of follow-up. The outcome of current large prospective randomised trials may confirm whether or not such follow-up is worthwhile and what form it should take.

Extracorporeal shock wave lithotripsy for difficult common bile duct stones: initial New Zealand experience.

AIM: Common bile duct (CBD) stones can usually be managed by open surgery, endoscopic retrograde cholangiopancreatography (ERCP) or radiological intervention. At times, however, these methods are either unsuccessful or inappropriate. We report our initial experience of extracorporeal shock wave lithotripsy (ESWL) for CBD stones that had either been unsuccessfully managed by conventional techniques, or in cases where these techniques were associated with a high level of risk. METHODS: A retrospective review of medical records of cases receiving ESWL for CBD was undertaken. The aspects reviewed were: indications, outcome and completions from the procedure. RESULTS: ESWL was used in the management of eight patients (three male, five female, age range 24-83, mean 54 years). The indications in five cases were failure of open surgery, ERCP or radiological techniques to clear the duct. In the other three cases, ERCP was unsuccessful and there was significant coincidental medical illness (morbid obesity with diabetes, and severe ischaemic heart disease). CBD clearance was achieved in seven cases. In one unsuccessful case, the duct was cleared after two open procedures. CONCLUSIONS: ESWL can be used to clear CBD stones. It should only be used, however, where prior CBD drainage has been achieved, preferably by endoscopic sphincterotomy. Morbid obesity is a relative contraindication to the use of ESWL. If ESWL fails, a period of time should be allowed to elapse before open surgery because of distortion of soft tissue planes. ESWL can be a useful technique in dealing with some difficult CBD stones.

A role for the bacterial outer membrane in the pathogenesis of Helicobacter pylori infection.

Helicobacter pylori infection in humans is associated with diverse of clinical outcomes which are partly attributed to bacterial strain differences. Secreted bacterial products are thought to be involved in the pathogenesis caused by this non-invasive bacterium. Electron microscopy of gastric biopsies from infected individuals revealed blebbing of the H. pylori outer membrane, similar to the process of outer membrane vesicle shedding which occurs when the bacterium is grown in broth. Porins, a class of proinflammatory proteins, were observed in the outer membrane vesicles. The VacA cytotoxin, which is produced by 50-60% of H. pylori strains and associated with increased pathogenesis of infection, was also found to be vesicle-associated and biologically active. This supports the hypothesis that these vesicles represent a vehicle for the delivery of damaging bacterial products to the gastric mucosa.

Protective effect of appendectomy on the development of ulcerative colitis: matched, case-control study.

PURPOSE: Appendectomy and cigarette smoking have been suggested to reduce the chance of developing ulcerative colitis. A case-control study was undertaken to determine the relative incidence of appendectomy in patients with ulcerative colitis. METHODS: This case-control study examined the incidence of appendectomy in patients with ulcerative colitis and patients attending an orthopedic outpatient clinic. RESULTS: Of 100 patients with ulcerative colitis, 75 pairs were matched for age, gender, and cigarette smoking. The ulcerative colitis group had an appendectomy rate of 8 percent (6/75), compared with 21 percent in the control group (P = 0.018). The odds ratio was 3.5 (95 percent confidence interval, 1.15-10.6). CONCLUSIONS: No previous study has examined the effect of appendectomy, controlling for cigarette smoking. This study confirms that appendectomy protects against or reduces the chance of development of ulcerative colitis. A possible immunological explanation for this effect is advanced.

Tumour cell wound distribution after colectomy in a porcine model.

BACKGROUND: Concerns over tumour implants have impeded the adoption of laparoscopic surgery for cancer. Explanations assume an increased number of malignant cells present in trocar wound sites. The following are tested in the present paper: (i) that the magnitude of wound contamination following surgery is related to the location of the tumour cells; and (ii) the surgical approach. METHODS: We have used a porcine sigmoid colectomy model to compare the number of tumour cells on laparoscopic wounds after resections in the presence of intraluminal, intramural and intraperitoneal 51Cr-labelled, fixed HeLa tracer cells. Open colectomies were also performed in the presence of intraperitoneal tracer cells and their numbers on laparotomy wound surfaces were determined by gamma counting. RESULTS: With intraperitoneal cells, laparotomies had 1087 (+/- 106) tracer cells per mm (n = 4) while trocar wounds had 103 (+/- 54) cells per mm (n = 10) (P > 0.05). Resection of intramural tumours resulted in lower trocar wound contamination (0.9 +/- 0.6 cells/mm, n = 3). Resection of colon including intraluminal tracer cells resulted in 2.9 +/- 2.1 cells/mm on trocar wounds (n = 3). CONCLUSIONS: More tumour cells were deposited on open than laparoscopic trocar wound surfaces. Also, the risk of wound implantation is less with intraluminal or intramural tumours than with intraperitoneal cells (P > 0.05).

Lack of protection following immunisation with H. pylori outer membrane vesicles highlights antigenic differences between H. felis and H. pylori.

Helicobacter pylori-induced inflammation is associated with the development of gastritis, peptic ulcer disease and gastric cancer in humans. Immunisation against this bacterium would ultimately have a major impact on H. pylori-related disease, notably global gastric cancer rates. To date, several potential H. pylori vaccine candidates have been identified. In this study, the Helicobacter felis/murine model was used to assess the immunogenicity of a previously undescribed H. pylori outer membrane vesicle fraction in immune protection.

Operative factors affecting tumor cell distribution following laparoscopic colectomy in a porcine model.

BACKGROUND: An increased risk of laparoscopic port wound tumor implantation in the presence of overt or covert abdominal malignancy has been identified. PURPOSE: A porcine laparoscopic colectomy model has been used to quantify the influence surgical practices may have on tumor cell implantation. METHODS: 51Cr-labeled, fixed HeLa cells were injected intraperitoneally before surgery. Tumor cell contamination of instruments, ports, security threads, and excised wound margins was assessed by gamma counting. RESULTS: Greatest contamination occurred in ports used by the operating surgeon under pneumoperitoneum (64 percent of all port wound tumor cells) and mechanical elevation (76 percent). Gasless surgery in patients in the head-down position increased the rostral accumulation of tumor cells in the abdomen and right upper quadrant port wound by 330 and 176 percent, respectively. Under pneumoperitoneum, port movement was the major contributor to port leakage and wound contamination (21 percent of total recovered wound tumor cells per port). Tumor cells were not carried in aerosol form. Instrument passage and the withdrawal of security threads through the abdominal wall increased port wound contamination 430 and 263 percent, respectively, over pneumoperitoneum control ports. Preoperative lavage reduced by 61 percent, but did not eliminate, wound contamination. CONCLUSION: This porcine model may be used to evaluate surgical factors for the impact on port wound contamination.

37 kBq 14C-urea breath test and gastric biopsy analyses of H. pylori infection.

BACKGROUND: The treatment of H. pylori-associated gastroduodenal disease is increasingly aimed at bacterial eradication which requires follow-up assessment of therapeutic effectiveness and re-infection. A simplified 37 kBq 14C-urea breath test for H. pylori infection has been developed. METHODS: The 37 kBq 14C-urea breath test was compared with biopsy urease (CLO) and histological analyses of gastric-biopsies obtained from 63 patients undergoing endoscopy. RESULTS: The 30-min breath test correlated closely with biopsy findings, had a sensitivity of 100%, a specificity of 95% and a positive predictive value of 92%. CONCLUSIONS: The simplified, low-dose, 14C-urea breath test is a convenient, low-cost, transportable means of facilitating the management of H. pylori-associated diseases.

Dual silver staining to characterise Helicobacter spp. outer membrane components.

Helicobacter pylori is a bacterial pathogen, estimated to infect half the world's population. The bacterium is the aetiological cause of gastritis, the common precursor for peptic ulcer disease and gastric cancer. Immunisation of at-risk individuals is the most cost-effective means of dealing with such a widespread pathogen. Potential vaccine candidates need to be identified and characterised. Conventional silver staining is commonly used for the sensitive detection of bacterial protein components separated by SDS-PAGE. Modified silver stains employing periodate oxidation have also been developed for the analysis of purified bacterial lipopolysaccharide. By using these methods in parallel, as a dual silver stain, bacterial fractions can be characterised in terms of protein and LPS content. Strain differences can also be readily identified by comparing protein and LPS profiles. When combined with differential immunoblotting, the dual silver stain is a useful analytical tool for characterising potential vaccine candidate antigens.

Tumor cell distribution following laparoscopic colectomy in a porcine model.

UNLABELLED: A clinically relevant, laparoscopic colectomy model has been developed to quantify surgical practices that may affect the incidence of port wound tumor implantation. METHODS: Suspended 51Cr-labeled, fixed HeLa cells were injected intraperitoneally into pigs before laparoscopic colectomies were performed with or without insufflation. Tumor cell contamination of instruments, ports, stability threads, and excised port wound margins was determined by gamma counting. RESULTS: Tumor cells were distributed throughout the peritoneal cavity, and the number detected at wound sites was directly related to number injected. Ports used by the operating surgeon had more cells than those used by the camera operator or assistant surgeon. Postoperative withdrawal of contaminated ports through abdominal wound was associated with an increase in port site contamination. Although the port site distribution of tumor cells was affected, mechanical elevation of abdominal wall did not eliminate contamination at any site. CONCLUSION: These results demonstrate application of the porcine model to test current surgical practices and measures that might be used perioperatively to reduce the numbers of intraperitoneal tumor cells or their distribution to specific sites during laparoscopic or open surgery.

The outcome of Helicobacter pylori infection.

Duodenal ulcer disease correlates strongly with Helicobacter pylori infection. Ulceration is not, however, a common result of H. pylori infection. Whether this is due to differences in the hosts or the strains of H. pylori remains at issue.

The fate of ingested 14C-urea in the urea breath test for Helicobacter pylori infection.

The metabolic fate of the radioactive carbon in the 14C-urea breath test for Helicobacter pylori was investigated in 18 subjects. After ingestion of labelled urea, breath was sampled for 24 h, and urine was collected for 3 days. Subjects were designated high or low expirers on the basis of their breath counts, and this agreed well with H. pylori serologic analyses. When given 185 or 37 kBq of 14C-urea, 51% (SD = 16%, n = 11) of the label was recovered from the breath of high expirers, and 7% (SD = 3%, n = 7) from the breath of low expirers. The mean combined urinary and breath recovery for high expirers was 86% (SD = 7%), and for low expirers it was 97% (SD = 3%). It is concluded that the long-term retention of 14C from ingested 14C-urea is low. The results enable a more accurate estimation to be made of radiation exposure resulting from the 14C-urea breath test.

Antibacterial action of the urease inhibitor acetohydroxamic acid on Helicobacter pylori.

The urease inhibitor acetohydroxamic acid (AHA) was assessed for its bacteriostatic and bactericidal effects on Helicobacter pylori. For eight isolates of H pylori, the minimum inhibitory concentration (MIC) was either 200 mg/l or 400 mg/l. Interactions between AHA and antimicrobial drugs used to treat H pylori were also determined. For most isolates AHA reduced the MIC for colloidal bismuth subcitrate (CBS), tetracycline, metronidazole, and amoxicillin. In a few isolates, however, AHA increased the minimum bactericidal concentration (MBC) for these antimicrobial treatments. In vitro AHA is active against H pylori and it interacts with other agents directed against H pylori.