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Biomedical subjects

P Hewett

Publications and source records attributed to P Hewett.

At least 19 recordsLinked to original sources
PubMed2004

Parastomal hernia repair.

OBJECTIVE: The aim of this study was to audit the results of parastomal hernia repair. METHODS: A retrospective review was made of all patients having parastomal hernia repair at 2 teaching hospitals over a 12-year period. RESULTS: Forty-three patients had 51 parastomal hernia repairs. Three types of hernia repair were used: 14 (28%) local suture, 19 (37%) local mesh repair and 18 (35%) stoma relocation. Three patients died and significant complications occurred in 65% of repairs. Parastomal hernia recurred in 18 (38%) of repairs. This was greatest with a sutured repair (59%) and least in patients having stoma relocation (24%). Repair with mesh was associated with a 39% recurrence rate. No significant statistical difference was found for the results of these repairs. CONCLUSION: Parastomal hernia repair is associated with high rates of morbidity, mortality and recurrence. Repair should not be undertaken without a good indication.

Adult↗
PubMed2003

Sentinel node biopsy for squamous-cell carcinoma of the anus and anal margin.

PURPOSE: The majority of anal tumors are squamous-cell carcinomas. These may be tumors of the anal canal or margin. They are best treated by combination of chemotherapy and radiotherapy. T1 and T2 tumors in this regime do not receive radiotherapy to the inguinal regions despite approximately 5 to 10 percent incidence of inguinal lymph node involvement. If the nodal status of the inguinal region could be accurately assessed, then a more tailored radiotherapy regime may be given. This article describes a novel method of assessment of the status of the inguinal lymph nodes in patients. METHODS: Patients with anal squamous-cell carcinoma had four injections of 0.2 ml of antimony sulfide (30 MBq) around the tumor. Under a gamma camera, a distant high-intensity signal was located, and this point was marked on the overlying skin using an indelible ink pen. In the operating theater, patent blue dye was injected all around the tumor. The localized lymph node was removed and sent for histopathology. RESULTS: This procedure was performed on 12 patients. The sentinel node was localized to the inguinal region and removed in eight of these patients. In two patients, metastatic squamous-cell carcinoma was identified histologically in the sentinel node. CONCLUSION: We advocate that this as a safe technique for detecting metastatic disease in the inguinal nodes in patients with anal squamous-cell carcinoma.

Adult↗
PubMed2002

Systematic review of dynamic graciloplasty in the treatment of faecal incontinence.

BACKGROUND: The aim of this systematic review was to compare the safety and efficacy of dynamic graciloplasty with colostomy for the treatment of faecal incontinence. METHODS: Two search strategies were devised to retrieve literature from the Medline, Current Contents, Embase and Cochrane Library databases up until November 1999. Inclusion of papers depended on a predetermined protocol, independent assessments by two reviewers and a final consensus decision. English language papers were selected. Acceptable study designs included randomized controlled trials, controlled clinical trials and case series. Forty papers met the inclusion criteria. They were tabulated and critically appraised in terms of methodology and design, outcomes, and the possible influence of bias, confounding and chance. RESULTS: No high-level evidence was available and there were no comparative studies. Mortality rates were around 2 per cent for both graciloplasty and colostomy. Morbidity rates reported for graciloplasty appear to be higher than those for colostomy. Dynamic graciloplasty was clearly effective at restoring continence in between 42 and 85 per cent of patients, whereas colostomy is, by its design, incapable of restoring continence. However, dynamic graciloplasty is associated with a significant risk of reoperation. CONCLUSION: While dynamic graciloplasty appears to be associated with a higher rate of complications than colostomy, it is clearly a superior intervention for restoring continence in some patients. It is recommended that a comparative, but non-randomized, study be undertaken to evaluate the safety of dynamic graciloplasty in comparison to colostomy, and that the procedure should be performed only in centres where it is carried out routinely.

Anal Canal↗
PubMed2001

Oncologic implications of laparoscopic and open surgery.

Although instrumental manipulation and mechanical tumor cell spillage seem to play the major role in port-site metastases from laparoscopic cancer surgery, minimally invasive procedures are used more and more in the resection of malignancies. However, port-site metastases also have been reported after resection of colon cancer in International Union Against Cancer (UICC) stage I [2, 14]. Therefore, changes in the peritoneal environment during laparoscopy also might influence intra- and extraperitoneal tumor growth during laparoscopy and pneumoperitoneum. Different results of experimental studies presented at the Third International Conference for Laparoscopic Surgery are analyzed and discussed.

Animals↗
PubMed2001

An unusual case of port site seeding.

We present an unusual case of a port site tumor from a colonic adenocarcinoma following laparoscopic cholecystectomy. A 66-year-old woman with a previous renal transplant underwent elective laparoscopic cholecystectomy for symptomatic cholelithiasis. Three months later, she re-presented with pain localized to the right lateral port wound. Subsequent investigation revealed an adenocarcinoma in the ascending colon with no evidence of local spread or liver metastases. The patient was enrolled in the ALCCAS trial (an Australasian multicenter prospective randomized clinical study comparing laparoscopic and conventional open surgical treatments of colon cancer in adults) and randomized to the laparoscopic arm. At laparoscopy, nodules of tumor were located at the sites of the previous right flank and umbilical trocar sites. The procedure was converted to an open hemicolectomy with excision of port sites. To our knowledge, only one other case of a colon carcinoma metastasizing to a port site following laparoscopic cholecystectomy has been reported. This case illustrates a number of points: (a) This was an advanced tumor at the time of diagnosis and was undoubtedly present at laparoscopic cholecystectomy. (b) This tumor was not manipulated at the time of laparoscopic cholecystectomy. (c) The patient was immunosuppressed at the time of laparoscopic cholecytstectomy. (d) The patient developed clinical recurrence in her laparotomy wound within 3 months of her open procedure. This case supports current arguments that the etiology of port site metastases is likely to be mulifactorial.

Adenocarcinoma↗
PubMed2001

Glyceryl trinitrate vs. lateral sphincterotomy for chronic anal fissure: prospective, randomized trial.

INTRODUCTION: Glyceryl trinitrate has been shown to be an effective treatment for chronic anal fissure. It decreases anal tone and ultimately heals anal fissures. The aim of this trial was to compare glyceryl trinitrate with lateral sphincterotomy (current standard treatment) as definitive management for chronic anal fissure. METHODS: All patients with symptoms of chronic anal fissure were randomly assigned to one of two treatment arms. The glyceryl trinitrate group applied 0.2 percent paste to the perianal area three times a day for eight weeks. Patients in the lateral sphincterotomy group underwent surgery on the next available operating list. Patients were reviewed at two weekly intervals until the fissure healed. RESULTS: Sixty-five patients were enrolled in the trial, with 31 in the lateral sphincterotomy group and 34 in the glyceryl trinitrate group. Five patients were excluded after randomization. Twenty of 33 (60.6 percent) glyceryl trinitrate patients had healed fissures in eight weeks compared with 26 of 27 (97 percent) in the sphincterotomy group (P = 0.001). Twelve patients in the glyceryl trinitrate group had little improvement in their symptoms and underwent lateral sphincterotomy. Poor tolerance and poor compliance with treatment were important factors in patients whose fissures did not heal with glyceryl trinitrate. Fissures healed significantly faster after sphincterotomy compared with glyceryl trinitrate treatment (P = 0.0001). Nine of the 20 patients whose fissures healed with glyceryl trinitrate paste subsequently had a recurrence of their fissures. There were no long-term complications from lateral sphincterotomy. CONCLUSION: Glyceryl trinitrate paste heals the majority of chronic anal fissures. However, a significant minority have little improvement or develop side effects and require conventional surgical treatment. Poor compliance with prescribed treatment often contributes to nonhealing. In addition, some fissures which initially heal with glyceryl trinitrate paste recur and require further treatment. Glyceryl trinitrate treatment is labor intensive for patients and physicians and has not been shown to be superior to lateral sphincterotomy.

Administration, Topical↗
PubMed2001

Misinterpretation and misuse of exposure limits.

Users of occupational exposure limits (OELs) often fail to distinguish between the complementary processes of risk assessment and exposure (risk) management. The former refers to those activities that lead to the selection of a reasonably protective exposure limit and often includes an analysis of exposure databases and an evaluation of group-based risk. The latter focuses on individual risk, and refers to those actions required of employers to ensure that each employee is unlikely to incur harm to health. This presentation focuses on how this failure to distinguish leads to misinterpretation and misuse of OELs. A typical OEL definition consists of at least three components: a concentration, an averaging time, and a target (usually the individual worker). OELs are occasionally improperly applied, resulting in a reduction of the expected level of protection. For example, sampling strategies proposed by the American Industrial Hygiene Association (AIHA) and Comité Européen de Normalisation (CEN) permit workers to be aggregated into exposure groups. Under certain circumstances this practice can leave some workers unevaluated and unprotected. Protection is also reduced when the averaging time is extended from a single shift to multiple shifts. Frequently, OELs are misinterpreted as upper limits to exposures averaged over weeks, months, or even years, rather than a single shift. Much of this confusion can be traced to the desire of some to reconcile research (epidemiology) sampling strategies with compliance sampling strategies. But the two have fundamentally different goals and objectives. Others are simply attracted to alternative OEL interpretations that permit frequent overexposures (i.e., measurements that exceed the OEL), thus making compliance easier. Given the current limitations of industrial hygiene and occupational epidemiology, and the general unwillingness of employers to routinely collect exposure data, OELs should continue to be defined as upper limits for single shift exposures. The current OEL model, which permits the use of proximate risk management goals to realize long-range objectives, should be retained. There are, however, valid reasons for augmenting this model to include criteria for evaluating compliance with long-range objectives. The augmented OEL model would be applicable to future new and revised OELs. The author suggests that OEL setting organizations consider harmonizing definitions and statistical interpretations for both existing and new OELs, thus minimizing future misinterpretation and misuse.

Europe↗
PubMed2001

Laparoscopic-assisted resection of colorectal malignancies: a systematic review.

OBJECTIVE: To compare the safety and efficacy of laparoscopic-assisted resection of colorectal malignancies with open colectomy. METHODS: Two search strategies were devised to retrieve literature from the Medline, Current Contents, Embase, and Cochrane Library databases until July 1999. Inclusion of papers was determined using a predetermined protocol, independent assessments by two reviewers, and a final consensus decision. English language papers were selected. Acceptable study designs included randomized controlled trials, controlled clinical trials, case series, or case reports. Fifty-two papers met the inclusion criteria. They were tabulated and critically appraised in terms of methodology and design, outcomes, and the possible influence of bias, confounding, and chance. RESULTS: Little high-level evidence was available. Laparoscopic resection of colorectal malignancy was more expensive and time-consuming, but little evidence suggests high rates of port site recurrence. The new procedure's advantages revolve around early recovery from surgery and reduced pain. CONCLUSIONS: The evidence base for laparoscopic-assisted resection of colorectal malignancies is inadequate to determine the procedure's safety and efficacy. Because of inadequate evidence detailing circumferential marginal clearance of tumors and the necessity of determining a precise incidence of cardiac and other major complications, along with wound and port site recurrence, it is recommended that a controlled clinical trial, ideally with random allocation to an intervention and control group, be conducted. Long-term survival rates need to be a primary aim of such a trial.

Colectomy↗
PubMed2000

Ultrasound of colonic neoplasia. An intraoperative tool?

BACKGROUND: The accuracy of intraoperative ultrasound of the colon in the location and assessment of neoplastic lesions at the time of resection has not been reported. METHODS: An in vitro study was performed, with ultrasound imaging of colonic specimens resected for malignancy. The specimens were imaged empty, surrounded by saline, the lumen filled with saline. RESULTS: Excellent ultrasound images were produced, particularly when the colonic lumen was filled with saline. All lesions were located by this technique, and several impalpable synchronous polyps also were found. In two specimens, the remnants of a malignant polyp not visible with intraoperative colonoscopy were found by specimen ultrasound. The clarity of the image was such that the cancer stage often could be assessed. CONCLUSIONS: Direct ultrasound of the colon, using a high-frequency intraoperative probe, produced accurate images of neoplastic lesions in an in vitro setting. This technique may have a role in the intraoperative location and assessment of colorectal cancer.

Colonic Neoplasms↗
PubMed2000

Inequality of child mortality among ethnic groups in sub-Saharan Africa.

Accounts by journalists of wars in several countries of sub-Saharan Africa in the 1990s have raised concern that ethnic cleavages and overlapping religious and racial affiliations may widen the inequalities in health and survival among ethnic groups throughout the region, particularly among children. Paradoxically, there has been no systematic examination of ethnic inequality in child survival chances across countries in the region. This paper uses survey data collected in the 1990s in 11 countries (Central African Republic, Côte d'Ivoire, Ghana, Kenya, Mali, Namibia, Niger, Rwanda, Senegal, Uganda, and Zambia) to examine whether ethnic inequality in child mortality has been present and spreading in sub-Saharan Africa since the 1980s. The focus was on one or two groups in each country which may have experienced distinct child health and survival chances, compared to the rest of the national population, as a result of their geographical location. The factors examined to explain potential child survival inequalities among ethnic groups included residence in the largest city, household economic conditions, educational attainment and nutritional status of the mothers, use of modern maternal and child health services including immunization, and patterns of fertility and migration. The results show remarkable consistency. In all 11 countries there were significant differentials between ethnic groups in the odds of dying during infancy or before the age of 5 years. Multivariate analysis shows that ethnic child mortality differences are closely linked with economic inequality in many countries, and perhaps with differential use of child health services in countries of the Sahel region. Strong and consistent results in this study support placing the notion of ethnicity at the forefront of theories and analyses of child mortality in Africa which incorporate social, and not purely epidemiological, considerations. Moreover, the typical advantage of relatively small, clearly defined ethnic groups, as compared to the majority in the national population, according to fundamental indicators of wellbeing--child survival, education, housing, and so forth--suggests that many countries in sub-Saharan Africa, despite their widespread poverty, are as marked by social inequality as are countries in other regions in the world.

Africa South of the Sahara↗
PubMed1999

Effects of video information on precolonoscopy anxiety and knowledge: a randomised trial.

BACKGROUND: The provision of information before medical or surgical procedures should improve knowledge and allay anxiety about the pending procedure. This trial aimed to assess the value of an information video in this process. METHODS: Patients scheduled to undergo colonoscopy were approached about 1 week before the procedure. All patients were given an information leaflet about colonoscopy, and completed a Spielberger state anxiety inventory (STAI) questionnaire to assess baseline anxiety. The patients were then randomly assigned to watch or not watch the information video. Immediately before colonoscopy, all patients completed a second anxiety questionnaire and a knowledge questionnaire. FINDINGS: 198 patients were screened. 31 declined to participate and 17 were unable to complete the forms. Of the remaining 150 patients, 72 were assigned the video, and 78 no video. The groups were similar with regard to age, sex, educational attainment, and initial anxiety score. Female patients had higher baseline anxiety than male patients (mean STAI 46.3 [95% CI 44.9-47.7] vs 36.9 [35.5-38.3]; difference 9.4 [7.8-12.2], p=0.0008). Patients who had not had a previous colonoscopy had higher baseline anxiety scores than those who had prior experience of the procedure (46.9 [45.4-48.5] vs 36.3 [34.7-37.9]; difference 10.6 [7.5-13.8], p=0.0008). Patients who watched the video were significantly less anxious before colonoscopy than those who did not. The former also scored more highly in the knowledge questionnaire than the latter with regard to the purpose of the procedure, procedural details, and potential complications of colonoscopy. INTERPRETATION: An information video increases knowledge and decreases anxiety in patients preparing for colonoscopy.

Adult↗
PubMed1999

Changes in microvessel endothelial cell gene expression in an in vitro human breast tumour endothelial cell model.

Selective targeting of tumour-endothelium has been proposed as a means of therapy. The successful exploitation of this approach will rely on the identification of suitable targets expressed specifically on the tumour-associated endothelium. In an attempt to identify novel tumour-endothelium associated targets we have used differential mRNA display to identify genes up-regulated in an in vitro breast tumour-endothelial cell culture model. Confluent monolayers of human mammary microvessel endothelial cells (HuMMEC) were incubated for 5 days with MDA-MB-231 breast adenocarcinoma cell-conditioned medium (TCM). mRNAs isolated from TCM-treated and control cells were amplified using 104 combinations of four 3(') anchored T(12)VN primers and 26 'random' 10mers by RT-PCR and the products examined on DNA sequencing gels. Seventy-four sequences were cloned and the differential expression of five genes was confirmed using dot-blots. These were identified as procollagen type-IV, Tie-2/Tek receptor tyrosine kinase, NADH dehydrogenase subunit-6, and ferritin heavy-chain, which were up-regulated, and insulin-like growth factor binding protein-5, which was down-regulated. Increased endothelial expression of basement membrane proteins and tyrosine kinase receptors is known to occur during angiogenesis. Our data support the use of this model for further in vitro investigation of tumour angiogenesis.

Journal Article↗
PubMed1999

Laparoscopic live donor nephrectomy: the preliminary experience.

BACKGROUND: Recent improvements in video technology and surgical instrumentation have resulted in the application of minimally invasive techniques to many surgical procedures including splenectomy and adrenalectomy. Nephrectomy requires a long flank incision with division of abdominal musculature and possible subcostal nerve damage. Severe postoperative pain and a prolonged recuperative period may result, and the cosmetic outcome may not be satisfactory. A new surgical approach utilizing laparoscopic dissection and delivery of the kidney through a small incision was performed to circumvent these problems. The aim of this paper is to describe the technique of laparoscopic live donor nephrectomy (LLDN) and present the preliminary outcome. METHODS: Over the 12-month period between May 1997 and April 1998, 16 donors underwent donor nephrectomy by a laparoscopic approach. The procedure was assessed with regard to its safety, feasibility and advantages over the open method. RESULTS: All the nephrectomies were completed without conversion to an open procedure. The average postoperative pain score on a visual analogue scale of 1-10 was 2 in LLDN. The donors required 36 mg morphine on average over 36 h postoperatively. Postoperative stay averaged 3 days. One donor developed an infective complication along the wound drain tract which settled with adequate drainage and antibiotics. All the removed donor kidneys were transplanted with immediate good function. There were no surgical complications or graft losses. The recipients' serum creatinine was in the range of 96-181 mmol/L 3 months after transplantation. CONCLUSIONS: Significant potential advantages of LLDN include less postoperative pain, shorter hospitalization and decreased recuperative time. This preliminary experience indicates LLDN to be effective in terms of safety and feasibility.

Blood Loss, Surgical↗