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Biomedical subjects

I M Macintyre

Publications and source records attributed to I M Macintyre.

At least 19 recordsLinked to original sources
PubMed1998

Does the mesh require fixation?

As the technique of laparoscopic mesh repair of groin hernia has evolved, the need for mesh fixation has been questioned. Staple fixation has resulted in nerve injury, and some recurrences have been attributed to the use of a mesh that is too small. Drawing on a successful experience from open preperitoneal techniques, laparoscopic surgeons are now reporting results using large mesh without fixation. Early reports show varying success with the technique. Although the problem of nerve damage has been solved, high recurrence rates are reported in which the technique has been used to repair recurrent hernias. Although further studies are required to establish the causes and natural history of mesh migration, initial experience with the technique appears promising.

Hernia, Inguinal↗
PubMed1997

Artificial neural networks applied to outcome prediction for colorectal cancer patients in separate institutions.

BACKGROUND: Artificial neural networks are computer programs that can be used to discover complex relations within data sets. They permit the recognition of patterns in complex biological data sets that cannot be detected with conventional linear statistical analysis. One such complex problem is the prediction of outcome for individual patients treated for colorectal cancer. Predictions of outcome in such patients have traditionally been based on population statistics. However, these predictions have little meaning for the individual patient. We report the training of neural networks to predict outcome for individual patients from one institution and their predictive performance on data from a different institution in another region. METHODS: 5-year follow-up data from 334 patients treated for colorectal cancer were used to train and validate six neural networks designed for the prediction of death within 9, 12, 15, 18, 21, and 24 months. The previously trained 12-month neural network was then applied to 2-year follow-up data from patients from a second institution; outcome was concealed. No further training of the neural network was undertaken. The network's predictions were compared with those of two consultant colorectal surgeons supplied with the same data. FINDINGS: All six neural networks were able to achieve overall accuracy greater than 80% for the prediction of death for individual patients at institution 1 within 9, 12, 15, 18, 21, and 24 months. The mean sensitivity and specificity were 60% and 88%. When the neural network trained to predict death within 12 months was applied to data from the second institution, overall accuracy of 90% (95% CI 84-96) was achieved, compared with the overall accuracy of the colorectal surgeons of 79% (71-87) and 75% (66-84). INTERPRETATION: The neural networks were able to predict outcome for individual patients with colorectal cancer much more accurately than the currently available clinicopathological methods. Once trained on data from one institution, the neural networks were able to predict outcome for patients from an unrelated institution.

Bias↗
PubMed1996

Extracolonic features of familial adenomatous polyposis in patients with sporadic colorectal cancer.

We have investigated the occurrence of attenuated extracolonic manifestations (AEMs) of familial adenomatous polyposis (FAP) in patients with non-polyposis colorectal cancer. In a prospective case-control study, we observed that significantly more colorectal cancer patients exhibited AEM than did age and sex-matched controls (19.5% vs 7.5%, P < 0.004). However patients with AEMs do not have occult FAP, as we found no heterozygous adenomatous polyposis coli (APC) gene mutations despite extensive analysis of constitutional DNA. Genome-wide DNA replication errors (RERs) occur in a proportion of colorectal cancers, particularly right-sided lesions and in almost all tumours from hereditary non-polyposis colorectal cancer (HNPCC) patients. As AEMs have been reported in familial colon cancer cases, we investigated the relationship of AEMs to tumour RER phenotype. There was indeed an excess of AEMs in patients with right-sided tumours (30.2% of 53 patients vs 14.7% of 116 patients, P < 0.03) and in those with RER tumours (3 out of 12 patients with RER tumours vs none out of 21 patients with non-RER tumours, P < 0.05). Two patients with AEM were from HNPCC families compared with none of those without AEM (P < 0.05). The association of AEMs with colorectal cancer is intriguing, and we speculate that it may be a manifestation of mutational mosaicism of the APC gene, perhaps associated with a constitutional defect in DNA mismatch pair.

Adenomatous Polyposis Coli↗
PubMed1995

Return to work after laparoscopic cholecystectomy.

To assess whether the introduction of laparoscopic cholecystectomy has led to a change in attitude regarding the resumption of normal activities after operation, the views of 407 general practitioners (GPs) and 532 patients were analysed. Although 99 per cent of GPs thought that laparoscopic cholecystectomy represented an improvement on the open operation, 55 per cent advised significant restrictions in the postoperative period. For the 231 patients in employment who had an uncomplicated laparoscopic procedure the mean time of return to work was 3.3 weeks. Although 47 per cent of patients returned to work within 2 weeks, 19 per cent took more than 4 weeks. The self-employed returned significantly earlier than employees. Education through better communication among hospital, general practitioners and patients is required if prevailing attitudes towards the length of convalescence after laparoscopic cholecystectomy are to change.

Attitude of Health Personnel↗
PubMed1995

Role of intraoperative cholangiography in laparoscopic cholecystectomy.

The results of a policy of selective cholangiography were assessed in 400 patients undergoing laparoscopic cholecystectomy. Preoperative endoscopic retrograde cholangiopancreatography (ERCP) was performed in 81 patients (20 per cent) of whom 31 (38 per cent) showed definite or possible evidence of stones in the bile duct. Seventeen of the 400 patients underwent intraoperative cholangiography and the majority of these (12) were normal. After a minimum follow-up of 1 year, 17 patients (4 per cent) have had ERCP for suspected residual duct stones. Eight (2 per cent) of these revealed stones and all were successfully treated with sphincterotomy and duct clearance. Preoperative and postoperative ERCP was not associated with mortality or major morbidity. No major duct injury occurred and none was diagnosed within 2 years of operation. Routine intraoperative cholangiography is not a necessary part of laparoscopic cholecystectomy in the presence of an efficient and safe ERCP service.

Adolescent↗
PubMed1995

Presentation of endometriosis to general surgeons: a 10-year experience.

The presentation and management of 24 patients with endometriosis (median age 34 (range 21-68)years) presenting to general surgeons over a period of 10 years (1985-1994) was reviewed. Patients presented with an abdominal wall swelling related to a previous Pfannenstiel incision (seven patients), umbilical swelling (four), inguinal canal swelling (two), incidentally following appendicectomy (five), terminal ileal obstruction (two), rectal bleeding (two) and urinary symptoms (two). Endometriosis was not suspected in most patients but was confirmed by surgical excision or resection with minimal morbidity. No recurrence occurred during a median follow-up of 53 (range 9-113) months. Endometriosis is a disease rarely seen by general surgeons and is often diagnosed incidentally or on histological examination. Cyclical symptoms associated with menstruation are present in 50 per cent of patients and should suggest the diagnosis in those presenting with scar-related and/or subcutaneous swellings. Simple excision or resection of the presenting lesion provides adequate treatment but, since pelvic endometriosis may be present, referral to a gynaecologist is recommended in every case.

Abdominal Muscles↗
PubMed1995

Critical appraisal and current position of laparoscopic hernia repair.

Laparoscopic hernia repair is still undergoing development and appraisal. This review briefly outlines the history of hernia repair. The six techniques of laparoscopic repair are described and published experience for each of these is discussed. The techniques, which involve simple closure of the neck of the hernial sac with or without closure of the internal ring, appear to have little or no place in adult practice. The plug technique and plug and patch technique represented a transient phase of development and have now been abandoned. Suture techniques have not been widely practised, making current appraisal difficult. Of the mesh techniques the intraperitoneal onlay mesh technique is not recommended. The place of the transabdominal preperitoneal technique and the extraperitoneal technique need to be determined by prospective randomized clinical trials.

Hernia, Inguinal↗
PubMed1994

Changing pattern of admission and operation for duodenal ulcer in Scotland.

To assess changes in the pattern of admission and operation for duodenal ulcer in Scotland, data recorded on Scottish Medical Records forms for the years 1975-1990 were analysed. The overall admission rate fell by 38 per cent from 157 to 98 per 100,000 population while the number of operations per year dropped by 80 per cent from 2955 to 582. There was a decline in perforation rate between 1975 and 1990 from 27 to 15 per 100,000 population. This general trend conceals a significant 93 per cent increase in the incidence of duodenal ulcer perforation among women aged 65 years and above, from 21 per 100,000 in 1975 to 41 per 100,000 in 1990 (r = 0.76, P < 0.001). There was a general trend towards a decline in haemorrhage rates, although this was significant only for men aged 15-44 years (r = -0.73, P < 0.01) and 45-64 years (r = 0.63, P < 0.04).

Adolescent↗
PubMed1994

Cholelithiasis and bile acid absorption after truncal vagotomy and gastroenterostomy.

Gallbladder disease in the form of gallstones demonstrated by ultrasonography or previous cholecystectomy was found in 15 of 26 women of median age 69 (range 52-82) years who had had truncal vagotomy and gastroenterostomy performed a median of 27 (range 11-30) years previously, compared with eight of 31 healthy age- and sex-matched controls drawn from the community (P < 0.02). Bile acid malabsorption identified by retention of 23-selena, 25-homotaurocholate (75SeHCAT) occurred in only two of the 26 patients after vagotomy and there was no relationship between retention and the presence or absence of gallbladder disease. The serum concentration of 7 alpha-hydroxycholestenone, an indicator of bile acid turnover, was significantly lower in patients with gallbladder disease after vagotomy than in controls (mean(s.e.m.) 19.1(3.7) versus 31.4(4.4) ng/ml, P < 0.05). Bile acid malabsorption does not play a significant role in the pathogenesis of gallstones after vagotomy but decreased bile acid synthesis may be important. There is no correlation between retention of 75SeHCAT and 7 alpha-hydroxycholestenone levels in patients after vagotomy, indicating that bile acid synthesis and absorption are uncoupled in this situation.

Absorption↗
PubMed1994

Reducing the risk of viral transmission at operation by electronic monitoring of the surgeon-patient barrier.

A new electronic device designed to detect glove holes, wet gowns and glove permeability was assessed during 50 general surgical operations. The cause of each alarm was recorded and the surgeon's awareness of any breach noted. Some 266 alarms were recorded of which 45 were ascribed to glove holes, 86 to wet gowns, 115 to glove porosity and 20 to other causes. Glove holes occurred in 29 of the 50 procedures; the surgeon was unaware of the hole in almost 70 per cent of cases. Holes were more common in laparotomy than in laparoscopic procedures (P = 0.006). In 20 per cent of instances surgeons did not respond immediately to the alarm (median delay 16 min). Six of eight surgeons who used the device indicated that they would do so regularly for major abdominal surgery. The electronic system accurately detects breaches in the surgeon-patient barrier. Its use should improve surgical discipline in acting to restore the barrier, protecting patient and surgeon alike.

Elective Surgical Procedures↗
PubMed1994

Death from malignant disease after surgery for duodenal ulcer.

A total of 2241 patients who had an operation for duodenal ulcer between 1947 and 1968 were followed up to determine the cause of death and to compare the observed number of deaths with the expected. Death certificates were traced for 1251 of 1387 known to have died. Observed deaths from all causes were significantly greater than expected (O/E 1.13) (95% CI 1.08 to 1.20). This was because of significant increases in deaths from neoplasms (O/E 1.25) (95% CI 1.13 to 1.39) and digestive diseases (O/E 1.71) (95% CI 1.11 to 2.59). Analysis of deaths from malignant disease showed an excess of deaths from carcinoma of lung (O/E 1.37) (95% CI 1.14 to 1.62) and from smoking related cancers (O/E 1.32) (95% CI 1.13 to 1.52) but there was no significant excess mortality from any other neoplasm. An excess of deaths within one year of the operation was seen from circulatory disease (O/E 1.85) (95% CI 1.17 to 2.78), respiratory disease (O/E 3.56) (95% CI 1.78 to 6.37), and digestive disease (O/E 21.46) (95% CI 13.75 to 31.93). These deaths are concentrated in the first postoperative month and as there is no excess mortality from circulatory, respiratory or digestive disease between 1 and 20 years postoperatively, show the direct effects of the operation as a cause of death. This together with the excess mortality from all respiratory disease confirms that excess mortality after duodenal ulcer surgery is, in the short term, the result of the operation itself and in the long term largely attributable to cigarette smoking. Operations for gastric ulcer largely account for the subsequent excess mortality from gastric cancer reported after peptic ulcer surgery. The findings do not support the theory that the operation has carcinogenic effects and do not support the case for routine endoscopic screening after operations for duodenal ulcer.

Adult↗
PubMed1993

Symptomatic outcome after laparoscopic cholecystectomy.

To evaluate the symptomatic outcome after laparoscopic cholecystectomy, a standard symptom questionnaire was sent to three patient groups at least 1 year after surgery: 115 patients had undergone laparoscopic cholecystectomy; 200 had undergone open cholecystectomy; and 200 had had inguinal hernia repair. Return of questionnaires was higher after laparoscopic cholecystectomy (100 of 115; 87.0 per cent) than the open procedure (167 of 200; 83.5 per cent) or hernia repair (163 of 200; 81.5 per cent). There was no difference in the number of patients who considered the operation to have cured or improved their preoperative symptoms after laparoscopic cholecystectomy (94 of 100; 94.0 per cent), open cholecystectomy (157 of 167; 94.0 per cent) or hernia repair (154 of 163; 94.5 per cent). Similar numbers considered their operation to have been a success (94.0, 95.2 and 94.5 per cent respectively). The prevalence of abdominal pain, nausea, flatulence, food intolerance and heartburn was similar in all groups of patients following operation. Diarrhoea occurred more often following laparoscopic (6.0 per cent) and open (4.2 per cent) cholecystectomy than hernia repair (1.2 per cent). Patients who underwent laparoscopic cholecystectomy tended to have a higher incidence of nausea or vomiting than those undergoing the open procedure, and consumed significantly more antacids (23.0 versus 12.0 per cent, P < 0.02). Laparoscopic cholecystectomy achieved the same rate of patient satisfaction as open cholecystectomy, with no apparent symptomatic advantage.

Cholecystectomy, Laparoscopic↗
PubMed1993

Laparoscopic cholecystectomy.

After laparoscopic cholecystectomy, the patient can expect a hospital stay of < 2 days and a return to work within 2 weeks. The associated operative mortality rate is low at < 0.2 per cent. The increased incidence of bile duct injury with the laparoscopic technique compared with open cholecystectomy is a cause for concern but such injuries should decrease with proper training in laparoscopic surgery. The use of operative cholangiography (whether routine, selective or never) is controversial but there is no evidence that routine cholangiography will prevent major bile duct injury.

Bile Ducts↗
PubMed1992

Laparoscopic cholecystectomy as a safe and effective treatment for severe acute cholecystitis.

OBJECTIVE: To evaluate the feasibility and safety of laparoscopic cholecystectomy in severe acute cholecystitis. DESIGN: Analysis of data collected prospectively from a consecutive series of 350 laparoscopic operations. SETTING: Two general surgical units in a teaching hospital. SUBJECTS: 31 patients with a diagnosis of severe acute cholecystitis based on clinical examination, investigation results, and operative findings. INTERVENTIONS: Initial intravenous fluids and broad spectrum antibiotics followed by laparoscopic cholecystectomy within 72 hours of presentation. MAIN OUTCOME MEASURES: Failure to complete the operation laparoscopically, length of postoperative stay in hospital, early postoperative morbidity, interval from operation to full activity, and return to work. RESULTS: Laparoscopic cholecystectomy was attempted in 19 patients with empyema of the gall bladder and 12 who had severe cholecystitis which failed to settle on medical management. A total of 29 operations were successfully completed with two conversions to open surgery. Two minor postoperative complications occurred, and one case of retained common bile duct stones with jaundice was treated by endoscopic retrograde cholangiopancreatography and papillotomy. Median postoperative hospital stay was two days, with return to normal activity in seven days and to work in two weeks. There were no deaths related to the operation. CONCLUSIONS: In the presence of severe acute cholecystitis laparoscopic cholecystectomy is feasible in most patients, with minimal risk of injury to surrounding structures and considerable benefits. It is recommended that laparoscopic cholecystectomy should be attempted in these patients when appropriate surgical skill is available.

Acute Disease↗