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Biomedical subjects

D I Watson

Publications and source records attributed to D I Watson.

At least 73 records · Page 4Linked to original sources
PubMed1999

Totally endoscopic Ivor Lewis esophagectomy.

Esophagectomy is associated with significant risks of perioperative morbidity and mortality, as well as prolonged convalescence due to effects of the incisions used for conventional surgical access. Because the outcome of this procedure is palliative in the majority of patients, it is possible that laparoscopic techniques could improve initial postoperative outcomes and therefore make surgery more acceptable for patients with esophageal cancer. A new technique is described for Ivor Lewis esophagectomy, which incorporates a hand-assisted laparoscopic approach for gastric mobilization and a thoracoscopic approach for esophageal dissection and anastomosis. Initial experience in two patients has been encouraging, with postoperative hospital stay and convalescence shortened.

Adenocarcinoma↗
PubMed1999

Prospective randomized double-blind trial between laparoscopic Nissen fundoplication and anterior partial fundoplication.

BACKGROUND: In the operative management of gastro-oesophageal reflux, a balance must be achieved between adequate control of reflux and excessive dysphagia. The ideal technique is not known. A randomized study was performed to determine whether laparoscopic anterior fundoplication is associated with a lower incidence of postoperative dysphagia than laparoscopic Nissen fundoplication, while achieving equivalent control of reflux. METHODS: Patients presenting for laparoscopic antireflux surgery were randomized to undergo either a Nissen fundoplication (n = 53) or an anterior 180 degrees hemifundoplication (n = 54). Patients were blinded to which procedure had been performed, and follow-up was obtained by a blinded independent investigator. Standardized clinical grading systems were used to assess dysphagia, heartburn and patient satisfaction 1, 3 and 6 months after operation. Objective measurement of lower oesophageal sphincter pressure, oesophageal emptying time, distal oesophageal acid exposure and endoscopic healing of oesophagitis was also performed. RESULTS: Operating time was similar for the two procedures (58 min for the Nissen procedure versus 60 min for anterior fundoplication). Resting and residual lower oesophageal sphincter pressures were lower following anterior fundoplication (29 versus 18 mmHg, and 13 versus 6 mmHg), and oesophageal emptying times were faster (92 versus 116 s). Acid exposure times and ability to heal oesophagitis were similar. At 3 months' follow-up clinical outcomes were similar for the two procedures. At 6 months, however, patients who had undergone anterior fundoplication experienced significantly less dysphagia for solid food and were more likely to be satisfied with the clinical outcome. CONCLUSION: Laparoscopic anterior fundoplication achieved equivalent control of reflux, more physiological postoperative manometry parameters, and an improved clinical outcome at 6 months. Continued follow-up remains necessary to confirm the long-term efficacy of the partial fundoplication procedure.

Double-Blind Method↗
PubMed1999

Laparoscopic reoperation following failed antireflux surgery.

BACKGROUND: The aim was to determine the feasibility of laparoscopic revision surgery following previous open and laparoscopic antireflux operations. METHODS: The outcome was determined for 27 patients (14 men, 13 women) who had undergone attempted laparoscopic revision between 3 months and 25 years after a previous antireflux operation. Median follow-up was 12 (range 3-48) months. RESULTS: Thirteen patients had previously had an open antireflux procedure (Nissen fundoplication, seven; transthoracic anatomical repair, five; Belsey procedure, one) and 14 a laparoscopic procedure (Nissen, 12; anterior partial fundoplication, two). The indications for revision were: recurrent reflux, 15; paraoesophageal hiatus hernia, six; troublesome dysphagia, six. Fifteen procedures comprised construction of a new Nissen fundoplication, six conversion from a Nissen to a partial wrap, three repair of a paraoesophageal hernia and three widening of the oesophageal hiatus. Revision was successfully completed laparoscopically in 12 patients following a previous laparoscopic procedure and in nine following a previous open operation. Median operating time was 105 min after previous open surgery and 80 min after laparoscopic surgery. No perioperative complications occurred in either group and a good outcome was achieved in 25 of the 27 patients. CONCLUSION: Laparoscopic reoperative antireflux surgery is feasible. Reoperation is likely to be more difficult following failure of an open procedure than a laparoscopic one.

Female↗
PubMed1999

Experimental study of the effect of intraperitoneal heparin on tumour implantation following laparoscopy.

BACKGROUND: Conclusions drawn from clinical reports of port site metastases following laparoscopic resection of intra-abdominal malignancy are now supported by a burgeoning experimental literature which suggests that laparoscopy promotes tumour metastasis to wounds. This study investigated the effect of intraperitoneal blood and heparin on the incidence of tumour cell implantation and port site metastasis. METHODS: Twenty-four Dark Agouti rats underwent laparoscopy with carbon dioxide insufflation and the instillation of a tumour cell suspension and/or blood into the peritoneal cavity. Rats were allocated randomly to one of the following study groups (six rats per group): (1) controls; (2) intraperitoneal blood (2 ml blood introduced from a syngeneic donor rat); (3) intraperitoneal heparin; (4) intraperitoneal blood and heparin. Rats were killed 7 days after the procedure, and the peritoneal cavity and port sites were examined for the presence of tumour. RESULTS: Tumour implantation and port site metastases were reduced by the intraperitoneal administration of heparin, but increased by the presence of intraperitoneal blood. CONCLUSION: The results of this study suggest that tumour implantation following laparoscopy is promoted by the presence of intraperitoneal blood and that this effect may be reduced by the use of intraperitoneal heparin.

Animals↗
PubMed1999

The role of peritoneal immunity and the tumour-bearing state on the development of wound and peritoneal metastases after laparoscopy.

BACKGROUND: The effect of the tumour-bearing state and alterations in peritoneal immune function on the incidence of port-site and peritoneal metastases was investigated after laparoscopy with and without CO2 pneumoperitoneum. METHODS: A suspension of viable adenocarcinoma cells was introduced into the left upper quadrant of the peritoneal cavity of syngeneic tumour-bearing rats at laparotomy, laparoscopy with CO2, and gasless laparoscopy. Control rats did not have pre-existing tumours. A group of non-tumour-bearing rats were also injected intraperitoneally with endotoxin 4 h before intraperitoneal tumour cell injection. Six days later the peritoneal cavity and surgical wounds were examined for macroscopic evidence of implanted tumour. Peritoneal macrophages were obtained from tumour-bearing rats subjected to different laparoscopic procedures and the activation state measured following exposure to lipopolysaccharide in vitro. RESULTS: In the control rats, tumour implantation in the surgical wounds and peritoneum was significantly greater in the rats that had undergone laparoscopy with CO2. The presence of a pre-existing tumour was associated with increased tumour spread in all treatment groups and at most sites. Injection of endotoxin also resulted in increased tumour spread. Peritoneal macrophages from control and tumour-bearing rats who underwent laparoscopy with CO2 produced significantly less TNF-alpha in vitro, compared to gasless laparoscopy or laparotomy. CONCLUSIONS: Carbon dioxide insufflation enhances tumour spread and implantation. The underlying immune or metabolic status of the host, as influenced by the tumour-bearing state or modification of the peritoneal environment, also has a marked independent effect on tumour spread and implantation. The immune and metabolic status of the peritoneum including the extent of macrophage activation is implicated in this effect.

Adenocarcinoma↗
PubMed1999

In vitro inhibition of tumour growth in a helium-rich environment: implications for laparoscopic surgery.

BACKGROUND: The recent results of several experimental studies have suggested that tumour implantation after laparoscopic surgery for intra-abdominal malignancy may be partly related to the chemical composition of the insufflation gas used during surgery. These studies have demonstrated that the use of helium as a laparoscopic insufflation agent for cancer surgery results in less tumour implantation and growth at port sites. To further investigate these findings, the present study was performed to compare the growth of cultured tumour cells after exposure to simulated laparoscopic environments, rich in helium, carbon dioxide (CO2), or air. METHODS: A rat mammary adenocarcinoma cell suspension was exposed to a simulated laparoscopic environment for 40 min in one of the following groups: (i) control (atmospheric air, equivalent to a 'gasless' laparoscopic environment); (ii) a CO2-rich environment; and (iii) a helium-rich environment. Cells were then cultured for 18 h and optical density readings were used to assess the number of viable tumour cells at the end of this period. The experiment was performed twice using an identical protocol to ensure consistency in the results. In a further study, pH was continuously measured using an antimony probe during a 40 min insufflation period and for 10 min after insufflation. RESULTS: Cell growth was significantly lower after incubation in the helium-rich environment compared to both the CO2 and control groups (P < 0.001). There was a significant decrease in pH in the CO2 group which was not observed during exposure to either air or helium. CONCLUSIONS: The inhibition of tumour growth in a helium-rich environment demonstrated by this study, and the reduced incidence of port-site metastases seen in other experimental studies, suggests that the clinical use of helium as an insufflation gas may have important advantages over CO2.

Adenocarcinoma↗
PubMed1999

Dietary interference with the use of Bilitec to assess bile reflux.

The Bilitec probe, which uses bilirubin as a marker for the detection of duodeno-oesophageal reflux, is subject to interference from strongly coloured foods, which can cause erroneously high bilirubin absorbance readings. To overcome this problem it is necessary to ingest a diet that is free from such substances. We tested the bilirubin absorbance of 32 different food substances in an in vitro environment, including many of the foods that are currently recommended for consumption during Bilitec studies. 'Dry' foods were blended with water, 'non-dry' solid foods were blended undiluted, and breakfast cereals were blended with milk. Blended mixtures were then tested for bilirubin absorption either undiluted or after mixing with hydrochloric acid. The 'absorbance' of weakly coloured foods was usually less than the commonly accepted threshold of 0.14, and the 'absorbance' of strongly coloured foods was usually above this. The 'absorbance' of three substances was higher in an acid environment. Three of the currently recommended foods had a sufficiently high 'absorbance' to interfere with readings in the clinical situation. Of the 32 substances tested, only 13 are suitable when the 'absorbance' threshold is set at 0.14. This number can be increased to 19 if the threshold is increased to 0.20. From the foods evaluated, enough are suitable at the 0.14 threshold to enable a suitable diet to be constructed for most patients. Furthermore, many potentially acceptable foods remain untested. Clarification of appropriate food substances will help patients to be aware which foods are safe to eat, so that food interference can be prevented during Bilitec studies.

Absorption↗
PubMed1999

Motility across esophageal anastomoses after esophagectomy or gastrectomy.

The esophageal motility of 23 patients who underwent esophagectomy or gastrectomy for carcinoma of the esophagus or gastroesophageal junction was recorded daily during the immediate post-operative period for high-pressure transients or other motility disturbances. Patients were divided into three subgroups according to the level of the esophageal anastomosis: group 1, neck (n = 4); group 2, thoracic (n = 14); group 3, diaphragmatic hiatus (n = 5). Peristalsis was absent in all patients studied during ventilation and sedation in the intensive care unit (five patients). Early post-operative esophageal motility after esophageal anastomosis varied somewhat with the length of residual esophagus. With short lengths of residual esophagus, no consistent motility pattern emerged. With longer lengths, early peristaltic activity was evident, but diminished over the first few post-operative days. Esophageal resection and anastomosis is associated with loss of peristalsis in the initial post-operative period, consistent with the concept of an esophageal ileus.

Adult↗
PubMed1999

A new surgical technique for the silicone gastric band in the presence of a large hiatus hernia.

BACKGROUND: The purpose of this study was to establish the efficacy of a new surgical technique for the placement of the silicone gastric band (LAP-Band) in the presence of a large (>5 cm) hiatus hernia. METHOD: Hiatus hernias >5 cm were identified by endoscopy and barium meal in 6 patients. Each patient underwent hiatal hernia repair and attempted gastrodesis with laparoscopic placement of a gastric band. RESULTS: At 6 months, there were no complications. Mean weight loss was 16 kg. CONCLUSION: Repair of hiatus hernia with hiatal repair and gastrodesis of the posterior aspect of the stomach may allow some patients to undergo a procedure previously considered contraindicated.

Adult↗
PubMed1998

Efficacy of cytotoxic agents for the prevention of laparoscopic port-site metastases.

BACKGROUND: Recent experimental studies support initial clinical impressions that laparoscopic surgery for malignant neoplasms may be associated with an increased incidence of metastases to port sites. This study investigated in an experimental model the influence of cytotoxic agents (administered intraperitoneally or intramuscularly) on the development of port-site metastases following laparoscopic surgery. METHODS: Seven days after the implantation of an adenocarcinoma in the left abdominal flank, 72 Dark Agouti rats underwent laparoscopy with carbon dioxide insufflation, instillation of an intraperitoneal agent, and intraperitoneal tumor laceration within the following study groups (12 rats in each group): (1) control (no intraperitoneal instillation); (2) intraperitoneal instillation of isotonic sodium chloride solution (0.9%); (3) intraperitoneal instillation of povodine-iodine (1:10 dilution of povidine-iodine and isotonic sodium chloride solution); (4) intraperitoneal instillation of methotrexate (0.125 mg of methotrexate in 3 mL of isotonic sodium chloride solution); and (5) intraperitoneal instillation of aqueous chlorhexidine acetate. Twelve additional rats underwent laparoscopic tumor laceration following intramuscular injection of 0.125 mg of methotrexate (no intraperitoneal agent). Rats were killed 7 days after the procedure, and the wounds were examined histologically by a blinded histopathologist for the presence of tumor metastases. RESULTS: No tumor was found in any port site following the intraperitoneal administration of povidine-iodine (P=.04). In contrast, port-site metastases developed in the control group (5 [41.7%] of 12), the isotonic sodium chloride solution group (4 [33.3%] of 12), the chlorhexdine group (4 [33.3%] of 12), the intraperitoneal methotrexate group (2 [16.7%] of 12), and the parenteral methotrexate group (5 [41.7%] of 12). CONCLUSIONS: The results of this study suggest that the development of metastases to port sites following laparoscopic surgery may be prevented by the intraperitoneal instillation of diluted povodine-iodine. Other agents failed to influence the incidence of port-site metastases. Further studies are needed to determine if these findings can be applied to humans.

Animals↗
PubMed1998

Intraoperative scintigraphic localization and laparoscopic excision of accessory splenic tissue.

The recent advent of laparoscopic splenectomy for the treatment of refractory idiopathic thrombocytopenic purpura (ITP) has been embraced by surgeons and hematologists in many institutions. However, the occurrence of accessory splenic tissue in a proportion of such splenectomies, either concurrently or later, raises the question of how to deal with this problem when it arises. We report that the laparoscopic approach, facilitated by lateral positioning, can be successfully used for the treatment of an accessory spleen causing recurrent ITP. The use of intraoperative nuclear imaging can greatly aid the localization and provide confirmation of complete excision of the nuclear focus, especially for a very small accessory spleen.

Adult↗
PubMed1998

Tumor implantation following laparoscopy using different insufflation gases.

BACKGROUND: Laparoscopic manipulation of malignancies is associated with an increased incidence of metastasis to port sites in experimental models. This study investigated the effect of different insufflation gases on the implantation of a tumor cell suspension following laparoscopic surgery in an established small animal model. METHODS: Forty Dark Agouti rats underwent laparoscopy and the introduction into the peritoneal cavity of a tumor cell suspension. The insufflating gas used for each procedure was one of the following gases (10 rats in each group): carbon dioxide (CO2), nitrous oxide (N2O), helium, and air. The rats were killed 7 days after surgery, and the peritoneal cavity and port sites were examined for the presence of tumor. RESULTS: Although no significant differences were seen between air, CO2, and N2O insufflation groups, tumor involvement of peritoneal surfaces was less likely following helium insufflation. CONCLUSION: The results of this study suggest that tumor metastasis to port sites following laparoscopic surgery may be influenced by the choice of insufflation gas. In this study, helium was associated with reduced tumor growth.

Adenocarcinoma↗
PubMed1998

Concurrent fluoroscopy and manometry reveal differences in laparoscopic Nissen and anterior fundoplication.

A prospective double-blind randomized trial was initiated to examine two types of laparoscopic fundoplication (Nissen and anterior). Thirty-two patients with proven gastroesophageal reflux disease presenting for primary laparoscopic antireflux surgery were randomized to undergo either Nissen fundoplication (N = 13) or anterior hemifundoplication (N = 19). Postoperative fluoroscopic and manometric examination was carried out concomitantly. Nissen fundoplication resulted in significantly greater elevation of resting (33.5 vs 23 mm Hg) and residual lower esophageal sphincter pressures (17 vs 6.5 mm Hg) and lower esophageal ramp pressure (26 vs 20.5 mm Hg) than the anterior partial fundoplication. A smaller radiologically measured sphincter opening diameter was seen following Nissen fundoplication (9 mm) compared with anterior fundoplication (12 mm). Lower esophageal ramp pressure correlated weakly (r = 0.37, P = 0.04) with postoperative dysphagia. It is concluded that the type of fundoplication performed significantly influences postoperative manometric and video barium radiology outcomes. The clinical relevance of this requires further investigation.

Barium Sulfate↗
PubMed1998

Efficacy of anterior, posterior and total fundoplication in an experimental model.

BACKGROUND: This study examined the effect of different types of laparoscopic fundoplication on an incompetent lower oesophageal sphincter to test their effectiveness at preventing gastro-oesophageal reflux in the early postoperative period. METHODS: An experimental porcine model was used. Initial oesophageal myotomy ensured an incompetent lower oesophageal sphincter with free reflux of 'intragastric fluid'. Anterior, posterior or total fundoplication was then performed laparoscopically in 15 laboratory pigs (five in each group). Fundoplication competence and efficacy were determined 2 weeks after laparoscopic antireflux surgery by inflating the stomach with liquid through a gastrostomy cannula. Some animals were also studied at 4 and 6 weeks. Lower oesophageal sphincter pressure was determined using a water-perfused oesophageal manometry catheter incorporating a Dent sleeve. RESULTS: All three types of fundoplication produced similar increases in postoperative resting lower oesophageal sphincter pressure and restored adequate competence to the gastro-oesophageal junction. CONCLUSION: All three variants of laparoscopic fundoplication restore gastro-oesophageal competence in the early postoperative period.

Animals↗
PubMed1998

Port-site metastases following laparoscopic surgery.

BACKGROUND: Application of laparoscopy to the resection of malignancy has been followed by a literature describing cases of metastatic involvement at laparoscopic port sites. These include patients who underwent surgery for early stage carcinoma and instances following laparoscopic procedures during which tumours were not dissected. METHODS: Recently published clinical and experimental studies, and case reports related to this problem are reviewed; their relevance is discussed. RESULTS: Experimental studies incorporating bench top and large animal models have confirmed that tumour cells may be redistributed to port sites during laparoscopic surgery either directly from contaminated instruments or indirectly via the insufflation gas. Small animal models suggest that the incidence of wound metastasis is increased following conventional laparoscopic surgery, and that it may be decreased by gasless laparoscopy or helium insufflation. This evidence suggests that the development of port-site metastases depends not only on the physical redistribution of tumour cells but also on the specific insufflation gas used, possibly because of influences on local metabolic or immune factors acting at the wound site. CONCLUSION: Further research in this area is urgent. Until the issue is better understood, patients undergoing laparoscopic surgery for malignancy should be entered into clinical trials.

Humans↗
PubMed1998

Antireflux surgery in the laparoscopic era.

BACKGROUND: The recent development of laparoscopic techniques for fundoplication has created renewed interest in surgery for gastro-oesophageal reflux disease, leading to reports of large clinical series from many centres. However, controversy remains about technical aspects of laparoscopic antireflux surgery, with no consensus yet reached about a standard operative technique. It is important, therefore, to reassess critically the results of laparoscopic surgery for reflux disease, so that its current status can be determined. METHODS: Published outcome studies for laparoscopic antireflux surgery, as well as selected studies from the era of open antireflux surgery, were reviewed to assess outcomes. RESULTS: The results of case series for laparoscopic antireflux surgery with short- and medium-term follow-up, as well as the early results of randomized trials, confirm that this approach reduces the early overall morbidity of surgery for reflux disease. However, certain complications may be more common, for instance paraoesophageal hiatus herniation, pneumothorax and oesophageal perforation, requiring surgeons to use specific strategies which can help to avoid these problems. Published studies and trials do not support the routine or selective application of a posterior partial fundoplication technique or routine division of the short gastric vessels during Nissen fundoplication. CONCLUSION: At present, a short loose Nissen fundoplication performed laparoscopically, with or without division of the short gastric vessels, is an appropriate surgical approach for gastro-oesophageal reflux disease. However, long-term outcomes following laparoscopic antireflux surgery will not be available for some years, and must be awaited before the final status of the various laparoscopic techniques can be confirmed.

Fundoplication↗