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Biomedical subjects

G Mathew

Publications and source records attributed to G Mathew.

At least 37 records · Page 2Linked to original sources
PubMed1998

Wound metastasis after laparoscopy with different insufflation gases.

BACKGROUND: There is growing evidence that laparoscopy for malignancy is associated with an increased incidence of metastasis to port sites. This study investigated the effect of different insufflation gases on port-site metastasis after laparoscopy in an established animal model. METHODS: Forty-eight Dark Agouti rats with an established adenocarcinoma in the left flank underwent laparoscopic intraperitoneal tumor laceration. The gas used for insufflation was one of the following (12 rats in each group): (1) CO2, (2) N2O, (3) helium, or (4) air. Rats were killed 7 days after the procedure, and the port sites were examined for the presence of tumor metastasis. RESULTS: Tumor involvement of port sites was significantly less likely after helium insufflation than in the other groups (p < 0.0001). There was no significant difference between the air, CO2, and N2O groups. CONCLUSIONS: This study suggests that the development of metastases in port sites after laparoscopy may be influenced in part by the choice of insufflation gas used to create the pneumoperitoneum. In particular, helium was associated with a reduced rate of metastases.

Adenocarcinoma↗
PubMed1998

Cassava fermentation and associated changes in physicochemical and functional properties.

Fermentation of cassava is an important processing technique followed in different parts of the world. Although fermentation is known to bring about vast changes in the physicochemical and functional properties of the tubers, attempts have seldom been made to consolidate and critically analyze the available information. Glaring inconsistencies and contradictions noticeable in some of the results reflect the differences and variations in the artisanal processes followed in the preparation of these products. It also stresses the need for a systematic study of not only the quoted products, but also a number of other fermented cassava products that have not been well documented.

Africa↗
PubMed1998

Peristalsis in an interposed colonic segment immediately following total oesophagogastrectomy.

BACKGROUND: The motility pattern of colon used for oesophageal replacement in an oesophagogastrectomy is thought to be altered following interposition. Whether this is the result of adaptation or the removal of motor control mechanisms is unknown. Motility patterns of the interposed colon during the immediate postoperative period have not been previously studied. METHODS: A patient who had an oesophageal adenocarcinoma and an unhealed gastric ulcer, underwent total gastrectomy and oesophagectomy. A colonic segment oriented isoperistaltically was used for oesophageal replacement. During the surgery, a customized 10 channel motility catheter was introduced transnasally into the colonic segment, and 24 h after surgery measurement of motor activity was undertaken using a perfused manometric system. RESULTS: Peristaltic contractions were observed with a mean contraction amplitude of 39.6 mmHg in the proximal channel, 90.3 mmHg in the distal channel and a mean propagation velocity of 0.51 cm/s. CONCLUSIONS: Peristaltic colonic contractions continue to occur in the early postoperative period in the colonic segment used to replace the oesophagus. In view of this, colon replacing the oesophagus should always be arranged in an isoperistaltic fashion.

Adenocarcinoma↗
PubMed1997

Gasless laparoscopy may reduce the risk of port-site metastases following laparascopic tumor surgery.

OBJECTIVE: To compare the incidence of port-site metastases in an experimental tumor model following tumor manipulation during laparoscopy aided by conventional insufflation with laparoscopy using a gasless technique. SETTING: An experimental model applied in a research laboratory. PARTICIPANTS AND INTERVENTIONS: Malignant tumors were implanted in the abdominal wall of 24 rats. Twelve rats underwent tumor laceration at laparoscopy with carbon dioxide insufflation, and 12 rats underwent the same procedure during gasless laparoscopy achieved by abdominal wall suspension. Rats were killed 1 week later and were examined for evidence of tumor metastases. The surgical wounds were examined microscopically by a histopathologist who was unaware of the operative technique used and the site of origin of the specimens. MAIN OUTCOME MEASURE: Histologically confirmed tumor metastasis to laparoscopic port wounds. RESULTS: Growth of the primary tumor was equal in both groups. Wound metastases were less likely in the gasless laparoscopy group (3 of 12 vs 10 of 12; P = .01, Fisher exact test). CONCLUSION: The use of laparoscopy without gas insufflation may reduce the risk of wound metastasis following laparoscopic surgery for cancer.

Animals↗
PubMed1997

A comparison of older longstay psychiatric and learning disability inpatients using the Health of the Nation Outcome Scales.

OBJECTIVE: With increasing longevity, the number of elderly patients with psychiatric or learning disabilities is likely to increase. The degree of overlap of symptoms and needs of these two groups of patients, which may allow for their care within the same service, was examined. DESIGN: Twenty-six longstay, elderly (> 65 years) psychiatric patients resident in psychogeriatric wards of a psychiatric hospital were compared with 23 longstay, elderly patients and 40 longstay patients aged 50-65 years, both resident in the wards of a specialist hospital for learning disabilities. The instrument used was the Health of the Nation Outcome Scales (HoNOS). RESULT: On the HoNOS, the elderly psychiatric patients scored significantly higher for problems with mood, relationships and occupation/activities. There were no significant differences for any of the scales rated between the 50-65 and > 65 years old patients with learning disabilities. CONCLUSION: The similarities between the three groups of patients would suggest that for some patients the same services may be utilized. This could reduce the cost of the care in the community and entail more economical use of the facilities and staff. The HoNOS proved to be a concise and simple instrument, which could become a useful tool in monitoring the outcome of healthcare in longstay patients.

Aged↗
PubMed1997

The effect of laparoscopy on the movement of tumor cells and metastasis to surgical wounds.

BACKGROUND: A variety of mechanisms have been proposed to explain tumor growth in port sites following laparoscopic cancer surgery. We devised two experimental models to determine whether carbon dioxide (CO2) insufflation during laparoscopic surgery influences the movement of tumor cells and leads to tumor implantation and growth in surgical wounds. METHODS: Model 1: Viable adenocarcinoma cells were introduced into the upper abdomen of six syngeneic immune-competent rats during laparoscopy with CO2 insufflation; the same procedure was followed for a further six rats during gasless laparoscopy. A length of plastic tubing introduced through the anterolateral aspect of the rats' left lower abdominal wall was used to vent the insufflation gas through the abdomen of a recipient rat for 30 min. After 21 days, the peritoneal cavity and surgical wounds of the recipient rat were examined for implanted tumor. Model 2: A suspension of radiolabeled adenocarcinoma cells was introduced into the upper abdomen of five rats during laparoscopy with CO2 insufflation and an additional five rats during gasless laparoscopy. A length of plastic tubing introduced through the anterolateral aspect of the left lower abdominal flank was used to vent the insufflation gas through phosphate-buffered saline solution. After 30 min, the solution was counted for radioactivity. RESULTS: Tumor growth occurred at the site of both the insufflation and venting ports in the second rat in five of the six rats from the group undergoing insufflation, but it was found in none of the gasless laparoscopy group (p = 0.015). In the second model, significant transfer of tumor cells to the vented gas occurred only in the rats undergoing laparoscopy with insufflation (median, 2.71% versus 0% of the introduced labeled cells; p = 0.008). CONCLUSIONS: Carbon dioxide insufflation results in tumor dissemination during laparoscopy, leading to port site metastasis. Gasless laparoscopy may prevent this problem.

Abdominal Muscles↗
PubMed1997

Comparison of anterior, posterior and total fundoplication using a viscera model.

OBJECTIVE: To determine the contribution of mechanical factors to the function of different types of fundoplication. DESIGN AND SETTING: An experimental bench-top study using abattoir-sourced pig esophagus and stomach placed on a tray. Preliminary esophageal myotomy ensured free reflux of 'intragastric fluid'. INTERVENTIONS: Anterior, posterior, and total fundoplications were performed on each of ten sets of viscera. MAIN OUTCOME MEASURES: Lower esophageal sphincter pressure was measured using a conventional esophageal manometry catheter. Intragastric pressure was measured with a single channel intragastric manometry catheter, whilst the stomach was inflated with coloured water. The maximum intragastric pressure or the pressure measured when the fundoplication yielded to gastric distension was recorded. RESULTS: All three types of fundoplication restored adequate competence to the gastroesophageal junction, although high-volume gastric infusions resulted in fundoplication yield in 4/10 anterior and 4/10 posterior fundoplications. Gastric distension resulted in fundal dilatation and consequent compression of the adjacent esophagus. Fundoplication generated a median rise of 11-13.5 mmHg in lower esophageal sphincter pressure, comparable to pressures reported in the postoperative clinical setting. Significantly greater intragastric volumes and pressures were tolerated following total fundoplication. CONCLUSIONS: This study suggests that mechanical factors could be major contributors to the ability of a fundoplication to restore gastroesophageal competence. Anterior, posterior and total fundoplications are all effective procedures.

Animals↗
PubMed1997

Prospective double-blind randomized trial of laparoscopic Nissen fundoplication with division and without division of short gastric vessels.

OBJECTIVE: To determine whether division of the short gastric vessels (SGVs) and full mobilization of the gastric fundus is necessary to reduce the incidence of postoperative dysphagia and other adverse sequelae of laparoscopic Nissen fundoplication. SUMMARY BACKGROUND DATA: Based on historical and uncontrolled studies, division of the SGVs has been advocated during laparoscopic Nissen fundoplication to improve postoperative clinical outcomes. However, this modification has not been evaluated in a large prospective randomized trial. METHODS: One hundred two patients with proven gastroesophageal reflux disease presenting for laparoscopic Nissen fundoplication were prospectively randomized to undergo fundoplication with (52 patients) or without (50 patients) division of the SGVs. Patients with esophageal motility disorders, patients requiring a concurrent abdominal procedure, and patients who had undergone previous antireflux surgery were excluded. Patients were blinded to the postoperative status of their SGVs. Clinical assessment was performed by a blinded independent investigator who used multiple standardized clinical grading systems to assess dysphagia, heartburn, and patient satisfaction 1, 3, and 6 months after surgery. Objective measurement of lower esophageal sphincter pressure, esophageal emptying time, and distal esophageal acid exposure and radiologic assessment of postoperative anatomy were also performed. RESULTS: Operating time was increased by 40 minutes (median 65 vs. 105) by vessel division. Perioperative outcomes and complications, postoperative dysphagia, relief of heartburn, and overall satisfaction were not improved by dividing the SGVs. Lower esophageal sphincter pressure, acid exposure, and esophageal emptying times were similar for the two groups. CONCLUSION: Division of the SGVs during laparoscopic Nissen fundoplication did not improve any clinical or objective postoperative outcome.

Deglutition Disorders↗
PubMed1997

Adverse impact of pneumoperitoneum on intraperitoneal implantation and growth of tumour cell suspension in an experimental model.

BACKGROUND: An investigation of the effect of laparoscopy and CO2 pneumoperitoneum on the pattern of tumour implantation and growth in the peritoneal cavity was carried out. METHODS: A suspension of viable adenocarcinoma cells was introduced into the left upper quadrant of the peritoneal cavity of 36 syngeneic immune-competent rats at laparotomy, laparoscopy with CO2 insufflation, and gasless laparoscopy (12 rats in each group). Six days later the peritoneal cavity and surgical wounds were examined for macroscopic evidence of implanted tumour. The abdominal cavity was divided into sectors and macroscopic tumour implantation was determined for each sector and wound. This was confirmed by histological examination. RESULTS: While tumour implantation occurred in the vicinity of the tumour suspension introduction site in the laparotomy and gasless laparoscopy groups, implantation occurred throughout the peritoneal cavity, including areas remote to the introduction site, in the laparoscopy with CO2 insufflation group. Tumour growth was more likely in the port wounds of rats undergoing laparoscopy with insufflation than without. CONCLUSIONS: In this model, CO2 insufflation during laparoscopy resulted in widespread tumour dissemination and implantation, when compared to laparotomy and gasless laparoscopy, supporting the postulate that wound metastasis and tumour spread may be more likely following laparoscopic cancer surgery in humans when CO2 insufflation is used.

Adenocarcinoma↗
PubMed1997

Behaviour disorder in an adolescent with terminal deletion of chromosome 3.

Individuals with terminal deletion of the long arm of chromosome 3 are rare and survival into adulthood has not been previously reported. A 15-year-old with this condition was studied and the difficulties in management of the manifest behaviours are described. This chromosomal abnormality may be associated with mental and functional deterioration as well as severe self-injurious behaviour, commencing in early childhood.

Activities of Daily Living↗
PubMed1997

Oesophageal motility before and after laparoscopic Nissen fundoplication.

BACKGROUND: Whilst oesophageal manometry outcomes following fundoplication performed by open techniques have been described, detailed reports of changes in manometric parameters following large series of laparoscopic Nissen fundoplication have yet to be described. METHODS: An analysis of oesophageal manometry studies performed on patients undergoing laparoscopic Nissen fundoplication at the Royal Adelaide Hospital was performed to quantitate the effect of surgery and to determine whether manometric indicators of adverse surgical outcome could be identified. The original manometric recordings from a subset of 103 patients were reviewed. Only patients who had undergone preoperative and postoperative examinations in this department, and assessment by an independent investigator using a standardized clinical questionnaire, were included in the study. RESULTS: Mean resting lower oesophageal sphincter (LOS) pressure increased from 8.5 to 21.5 mmHg (P < 0.0001) following surgery, the mean residual pressure after sphincter relaxation (residual relaxation pressure) increased from 1.2 to 10.8 mmHg (P < 0.0001), and oesophageal 'ramp' pressure increased from 10.5 to 20.5 mmHg (P < 0.0001). Before operation 88 patients (85 per cent) propagated seven or more of ten wet swallows (normal peristalsis) versus 83 (81 per cent) after operation. Of the 15 patients with abnormal peristalsis before surgery, eight regained normal peristalsis after operation, whereas 13 of 88 patients with normal preoperative peristalsis subsequently had defective postoperative peristalsis. Raised postoperative residual relaxation pressure (r = 0.20) but not LOS pressure correlated significantly with postoperative dysphagia for liquids. None of the measured manometric parameters correlated with adverse outcomes such as postoperative dysphagia for solids, patient dissatisfaction or gas bloat. CONCLUSION: Whilst this study documents significant changes in LOS pressure following laparoscopic Nissen fundoplication, a clinically significant correlation between manometric outcome and clinical outcome was not demonstrated.

Adult↗
PubMed1996

Wound metastases following laparoscopic and open surgery for abdominal cancer in a rat model.

The recent application of laparoscopic resection techniques to malignant disease has raised safety concerns due to metastasis to surgical access wounds. The significance and incidence of this problem are controversial. In the present study a rat model, in which an implanted tumour was lacerated, was used to investigate whether application of laparoscopic techniques for malignant abdominal disease leads to an increased risk of tumour dissemination and implantation within the peritoneal cavity, and abdominal wall wounds. Malignant cells were implanted into the abdominal wall of 42 rats, resulting 7 days later in the growth of a tumour measuring 20-25 mm in diameter. There were three control groups: no surgery (n = 6); blunt manipulation of the tumour laparoscopically (n = 6); and blunt manipulation of the tumour at laparotomy (n = 6). Twenty-four rats underwent surgical laceration of the tumour capsule at either laparoscopy (n = 12) or laparotomy (n = 12). All rats were killed 1 week later, and examined for macroscopic evidence of tumour metastasis. The abdominal surgical wounds were excised for independent microscopic examination by a histopathologist. Growth of the primary tumour was greater in rats that had an operation than in unoperated controls, and was greater after laparotomy. However, wound metastases were five times more likely after laparoscopic tumour laceration than after the same procedure through an open incision (ten of 12 rats versus two of 12, P = 0.0033). Wound metastases following laparoscopic tumour manipulation are an important and real problem, with significant implications for the application of laparoscopic techniques to excise malignant disease in humans.

Abdominal Muscles↗
PubMed1996

Changes in fibrinogen levels in patients undergoing open and laparoscopic Nissen fundoplication.

BACKGROUND: Venous thromboembolic complications may be more common after laparoscopic surgical techniques, possibly due to changes in venous flow and blood coagulability. METHODS: This study assessed fibrinogen, cross-linked fibrin degradation products (D-dimer), prothrombin international normalized ration (INR), activated partial thromboplastic time (APTT) and platelets, during and after both open and laparoscopic Nissen fundoplication to determine whether coagulability is increased by the laparoscopic approach. RESULTS: Seven patients underwent open and thirteen underwent laparoscopic Nissen fundoplication. Fibrinogen levels following open fundoplication fell from 2.8 +/- 0.3 g/L pre-operatively to 2.0 +/- 0.3 g/L following skin incision, and then increased to 4.1 +/- 0.4 g/L on the first postoperative day. Similar changes in fibrinogen occurred following laparoscopic fundoplication (2.7 +/- 0.2, 2.5 +/ 0.2 and 3.8 +/- 0.4 g/L, respectively). No significant changes in the other coagulation indices were observed. CONCLUSIONS: These results demonstrate hypercoagulability on the first postoperative day, irrespective of the operative technique. No differences between the results following laparoscopic and open fundoplication were demonstrated.

Adult↗
PubMed1996

Laparoscopic surgery for gastro-oesophageal reflux: beyond the learning curve.

From September 1991 to October 1995, 320 Nissen fundoplications were undertaken laparoscopically by 12 surgeons at a single institution. To assess the performance of the procedure in the hands of five 'experienced' surgeons, the first 20 procedures performed by each surgeon or surgical trainee were excluded, providing a group of 174 patients for review. A short loose 360 degrees fundoplication was performed in all instances, with short gastric vessel division performed in 35.0 per cent of patients and hiatal repair in 66.7 per cent. Median operating time was 80 (range 30-210) min and median postoperative stay was 3 (range 1-19) days. Sixteen procedures (9.2 per cent) could not be completed laparoscopically and required conversion to open surgery. Some 144 patients were reviewed by a scientific officer 3 months after surgery, 85 at 12 months, and 32 at 2 years, using a standard clinical questionnaire. All but one were free from reflux symptoms, although 20.1 per cent reported some dysphagia at 3 months' follow-up; this figure declined to 11 per cent at 12 months and 6 per cent (two of 34 patients) at 2 years. At each follow-up interval, 91 per cent of patients were satisfied with the outcome of the surgery. Objective testing with oesophageal motility (75 patients) and barium swallow (113) studies 3-6 months after surgery confirmed the clinical outcome. Complications occurred in nine patients (5.2 per cent); four (2.3 per cent) of these required a subsequent operation within 30 days of surgery for bleeding (one patient), paraoesophageal herniation (one) and dysphagia (two). A further procedure was necessary in six other patients (3.4 per cent) for late problems, including paraoesophageal herniation (two), hiatal stenosis (three) and gastric obstruction (one). Revision was performed laparoscopically in two patients. The clinical results of laparoscopic Nissen fundoplication by 'experienced' laparoscopic surgeons were comparable with those of open surgery.

Adolescent↗
PubMed1995

Impact of laparoscopic cholecystectomy in a major teaching hospital: clinical and hospital outcomes.

OBJECTIVE: To compare the clinical, training and cost implications of laparoscopic cholecystectomy with open cholecystectomy. SETTING: A university teaching hospital. DESIGN: A retrospective review of all patients who underwent cholecystectomy in 1989, before the introduction of the laparoscopic technique, and in 1993, after the learning curve for laparoscopic cholecystectomy had been overcome. MAIN OUTCOME MEASURES: Surgical indications, feasibility of laparoscopic approach, type of surgeon, operating time, hospital stay, postoperative complications, and cost analysis. RESULTS: 240 cholecystectomies were performed in 1989 and 293 in 1993. This is a 22% increase in overall workload and includes a significant increase (85%; P < 0.0001) in elective caseload. In 1993, 89% of patients underwent laparoscopic surgery, with conversion to open cholecystectomy in 6.8% of elective patients and 33% of emergency patients. Surgical indications remained the same, as did the time from diagnosis to cholecystectomy. There were significant changes in median length of hospital stay (from 10 days in 1989 to 4 days in 1993; P < 0.0001), successful intraoperative cholangiography (93% versus 73%; P < 0.0001), and exploration of the common bile duct (15% versus 5% of patients; P = 0.0005). The number of cholecystectomies performed by surgeons-in-training decreased from 65% to 40%, individual treatment costs were reduced by 62% and overall hospital costs were reduced by 53%. Complications fell from 12% to 7% (P = 0.07), with the only major bile duct injury occurring in 1989. There were three deaths in 1989 and two deaths in 1993. All deaths followed open surgery. CONCLUSIONS: Laparoscopic cholecystectomy is associated with improved patient outcomes and, despite the increased workload, significant savings for hospitals.

Cholecystectomy↗