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Biomedical subjects

D I Watson

Publications and source records attributed to D I Watson.

At least 91 records · Page 5Linked 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

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

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

Hand-assisted laparoscopic vertical banded gastroplasty. Initial report.

Laparoscopic approaches to surgery for morbid obesity offer to reduce the morbidity associated with conventional weight reduction surgery. This paper describes a hand-assisted laparoscopic technique for vertical banded gastroplasty, a method which shortens and simplifies the laparoscopic approach to this established open surgical procedure.

Abdominal Muscles↗
PubMed1997

Laparoscopic versus open splenectomy for immune thrombocytopenic purpura.

BACKGROUND: We sought to determine whether laparoscopic techniques can reduce the operative morbidity of surgery in patients undergoing splenectomy for immune thrombocytopenic purpura (ITP). METHODS: All patients (60) undergoing splenectomy for ITP at the Royal Adelaide Hospital from January 1985 to November 1995 were reviewed. Results of patients undergoing open operation were obtained by means of retrospective case note review, whereas details of all patients undergoing laparoscopic splenectomy were collected prospectively and maintained on a computerized database. RESULTS: Forty-seven patients underwent splenectomy with an open technique and 13 with a laparoscopic technique. Patient groups were demographically similar. All laparoscopic procedures were completed with the laparoscopic technique. An accessory spleen was also removed at laparoscopic operation from two (15%) patients and at open operation from three patients (6%). Two more accessory spleens were missed at the original procedure, one at open operation and one at laparoscopic operation. These required later removal by using open and laparoscopic techniques, respectively. Blood and platelet transfusion requirements were reduced by the laparoscopic approach. Although mean operating times were similar (87 versus 88 minutes), laparoscopic splenectomy was associated with a greatly reduced postoperative hospital stay (10 versus 2 days, median; p < 0.0001) and no major morbidity. Long-term normalization of platelet counts was similar for the two techniques. The laparoscopic approach resulted in a reduction in hospital treatment costs from $4224 to $2238 per case (cost savings of $1986 per case). CONCLUSIONS: Laparoscopic splenectomy results in improved clinical outcomes and reduced costs for patients undergoing elective splenectomy for ITP.

Adolescent↗
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

Outcome of laparoscopic Nissen fundoplication in patients with disordered preoperative peristalsis.

BACKGROUND: A 360 degrees or Nissen fundoplication remains controversial in patients with disordered peristalsis, some surgeons preferring a partial wrap to minimise postoperative dysphagia. AIM: To evaluate symptoms and manometric outcome in patients with disordered peristalsis after Nissen fundoplication. PATIENTS: In an initial series of 345 patients studied prospectively, 31 patients who had undergone a Nissen fundoplication had disordered peristalsis. Using preoperative manometry, patients were classified as: equivocal primary peristalsis (eight patients); abnormal primary peristalsis (four patients); abnormal maximal contraction pressure (13 patients); abnormal primary peristalsis and maximal contraction pressure (six patients). METHODS: Postoperatively, patients underwent a barium meal, oesophageal manometry and standardised clinical review by a blinded scientific officer. RESULTS: Twenty eight (90%) patients had satisfaction scores of at least 8 out of a maximum of 10 and all would undergo surgery again. Whereas 15 (48%) patients had dysphagia scores greater than 4/10 preoperatively, only two (6%) had these scores at one year. Improved peristalsis was seen in 78% of postoperative manometric studies, and mean preoperative lower oesophageal sphincter pressure increased from 6.6 (range 0-21) mm Hg to 19 (4-50) mm Hg. CONCLUSIONS: These results are similar to the overall group of 345 patients and suggest that disordered peristalsis, and possibly even absent peristalsis, is not a contraindication to Nissen fundoplication as performed in these patients.

Adult↗
PubMed1997

Illness behavior influences the outcome of laparoscopic antireflux surgery.

BACKGROUND: While gastroesophageal reflux is amenable to medical and surgical treatment, the severity of pathophysiologic changes of the disease correlates poorly with the symptomatology. Similarly, the overall successful outcome of surgical therapy can be lessened by the poor outcome in a small number of patients despite the technical success of the operation. We conducted a study to determine the influence of illness behavior on the outcome and efficacy of laparoscopic Nissen fundoplication. STUDY DESIGN: From a larger group of patients undergoing a laparoscopic Nissen fundoplication, 77 patients (57 male, 20 female) completed an illness behavior questionnaire before and after surgery. This previously validated questionnaire assessed 10 scales of illness behavior. The results were compared with visual analog scales of outcome for overall satisfaction, heartburn, and solid food dysphagia, which were elicited independently from a standardized clinical follow-up questionnaire. RESULTS: Patients completed the questionnaire on average 2 months before and 25 months after surgery. High preoperative and postoperative scores for the "affective" and "hypochondriacal" scales were associated with poorer satisfaction with the surgical outcome. Although successful relief of reflux symptoms was unrelated to any preoperative illness behavior scale, postoperative scores for "disease conviction" and "disease affirmation" were predictors of further symptomatic heartburn in a small group of patients. Dysphagia did not correlate with illness behavior. When preoperative and postoperative scores were compared, no change in illness behavior was demonstrated, with the exception of lower scores for disease conviction and disease affirmation. CONCLUSIONS: These results suggest that while patient perception of disease is improved by laparoscopic fundoplication, patient satisfaction with the surgical outcome is in part determined by preoperative illness behavior.

Female↗
PubMed1997

Preoperative endoscopic grading of esophagitis versus outcome after laparoscopic Nissen fundoplication.

OBJECTIVES: Preoperative grading of esophagitis has recently been advocated as a means of selecting patients suitable either for laparoscopic Nissen fundoplication for patients with uncomplicated esophagitis, or for open operations in patients with complicated esophagitis (stricture or Barrett's esophagus). This study was performed to determine whether the degree of esophagitis preoperatively influences the clinical outcome after laparoscopic Nissen fundoplication. METHODS: Two hundred thirty-one patients who underwent a laparoscopic Nissen fundoplication were classified into three groups according esophagitis grade. Of these patients, 59 had no evidence of endoscopic esophagitis (group 1), 148 had uncomplicated esophagitis (group 2), and 24 had Barrett's esophagus or an esophageal stricture (group 3). Postoperative clinical assessment of heartburn, dysphagia, and patient satisfaction using visual analogue scales was performed by an independent investigator. RESULTS: No significant differences were found between the groups in regard to their clinical outcome. CONCLUSIONS: We conclude that laparoscopic Nissen fundoplication is a suitable approach for all patients with objectively proven gastroesophageal reflux disease selected for surgery, irrespective of their preoperative esophagitis grade.

Adolescent↗
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

Laparoscopic resection of benign tumors of the posterior gastric wall.

Laparoscopic wedge excision of benign gastric tumors using stapling instruments alone is not feasible for distal lesions and some tumors arising from the posterior gastric wall. An alternative transgastric approach to distal posterior wall lesions utilizing an anterior gastrotomy for access has been successfully applied in two reported cases.

Aged↗
PubMed1996

A learning curve for laparoscopic fundoplication. Definable, avoidable, or a waste of time?

OBJECTIVE: The objective of this study was to determine whether a learning curve for laparoscopic fundoplication can be defined, and whether steps can be taken to avoid any difficulties associated with it. SUMMARY BACKGROUND DATA: Although early outcomes after laparoscopic fundoplication have been promising, complications unique to the procedure have been described. Learning curve problems may contribute to these difficulties. Although training recommendations have been published by some professional bodies, there is disagreement about what constitutes adequate supervised experience before the solo performance of laparoscopic antireflux surgery, and the true length of the learning curve. METHODS: The outcome of 280 laparoscopic fundoplications undertaken by 11 surgeons during a 46-month period was assessed prospectively. The experience was analyzed in three different ways: 1) by an assessment of the overall learning experience within chronologically arranged groups, 2) by an assessment of all individual experiences grouped according to the experience of individual surgeons, and 3) by a comparison of early outcomes of operations performed by the surgeons who initiated laparoscopic fundoplication with the early experience of surgeons beginning laparoscopic fundoplication later in the overall institutional experience. RESULTS: The complication, reoperation, and laparoscopic to open conversion rates all were higher in the first 50 cases performed by the overall group, and in the first 20 cases performed by each individual surgeon. These rates were even higher in the initial first 20 cases, and the first 5 individual cases. However, adverse outcomes were less likely when surgeons began fundoplication later in the overall experience, when experienced supervision could be provided. CONCLUSIONS: A learning curve for laparoscopic fundoplication can be defined. Experienced supervision should be sought by surgeons beginning laparoscopic fundoplication during their first 20 procedures. This should minimize adverse outcomes associated with an individual's learning curve.

Clinical Competence↗