Preoperative shuttle walking testing and outcome after oesophagogastrectomy.

BACKGROUND: Objective assessment of cardiorespiratory reserve has been recommended before major surgery to identify patients with impaired oxygen delivery who may be at increased operative risk. Access to formal cardiopulmonary exercise (CPX) testing is limited outside larger centres. Following a previous audit of morbidity and mortality after oesophagectomy, we decided to add a simpler form of exercise test to our preoperative screen and review the outcomes. METHODS: Fifty-one patients who had surgical resection of an oesophageal cancer in our unit between April 2002 and April 2005 carried out an incremental shuttle walk exercise test before operation. Thirty-day outcome data were collected for each patient. RESULTS: Overall mortality in the group was 10%. No patient who walked 350 m or more died within 30 days. Five of the eight patients who could not achieve this distance died and two others remained in the critical care unit at 30 days. CONCLUSION: Preoperative shuttle walk testing using a standard protocol appears to be a sensitive indicator of operative risk in this group of patients. The apparent threshold value of 350 m is consistent with previously reported measures of functional capacity obtained using formal CPX testing.

Factors influencing the establishment of tumour-infiltrating lymphocyte cultures from human breast carcinoma and colon carcinoma tissue.

Tumour-infiltrating lymphocytes (TIL) were obtained from breast and colon tumour tissue and cultured in vitro in the presence of recombinant human interleukin-2. Seven of 35 breast tumours and five of 41 colon TIL cultures were established in vitro: proliferation rates of greater than 10(3) were achieved. The cytotoxic capacity of these cells was determined against the cell lines K562 and SW742, and percentage cytotoxicity levels of greater than 97% and 79%, respectively, were seen. An inverse relationship between the ability of TIL to kill and their proliferative capacity was observed in all cultures. The prominent phenotype was CD3 positive, with greater than 55% of TIL expressing this antigen; there was no expression of CD16. The expression of CD56 and CD25 varied, being maximumly expressed on 64% and 38% of TIL, respectively. When greater than 90% of TIL expressed CD3, the ability of the culture to kill the target cell lines was low; only when there was an increase in the proportion of cells expressing CD56 and a decrease in the expression of CD3 was there high cytotoxicity. This study indicates that the TIL which proliferate in vitro in the presence of interleukin-2 are not necessarily the mediators of cytotoxicity.

Endoscopic ablation of Barrett's oesophagus: a randomized-controlled trial of photodynamic therapy vs. argon plasma coagulation.

BACKGROUND: Barrett's oesophagus is the major risk factor for oesophageal adenocarcinoma. 5-Aminlevulinic acid-induced photodynamic therapy and argon plasma coagulation have been shown to be effective for ablating Barrett's oesophagus, but a comparative trial of these two modalities has not been reported. AIMS: To compare photodynamic therapy and argon plasma coagulation for the ablation of Barrett's oesophagus. METHODS: A total of 68 patients (54 male, 14 female; median age 61) with Barrett's oesophagus were randomized to photodynamic therapy (n = 34) or argon plasma coagulation (n = 34). Photodynamic therapy was performed using 5-aminlevulinic acid (30 mg/kg) and red light. Argon plasma coagulation was administered at a power setting of 65 W. Multiple treatment sessions were performed, with follow-up to 24 months. RESULTS: All patients showed a macroscopic reduction in the area of Barrett's oesophagus. This was greatest in the argon plasma coagulation group with 33 of 34 (97%) ablated, compared with 17 of 34 (50%) in the photodynamic therapy group; in the remainder, there was a reduction in the length of Barrett's oesophagus (median 50%, range: 5-90). Buried glands were found in 24% of photodynamic therapy patients, and in 21% of argon plasma coagulation patients. The median follow-up is 12 months (range: 6-24). CONCLUSIONS: Photodynamic therapy and argon plasma coagulation are both effective for ablating Barrett's oesophagus. Argon plasma coagulation appears more effective than photodynamic therapy, but the impact of both on carcinoma development requires larger studies with long-term follow-up.

Ablation treatment for Barrett oesophagus: what depth of tissue destruction is needed?

AIM: To establish the depth of Barrett's columnar epithelium and normal squamous oesophageal epithelium, in order to determine the depth of destruction required in ablation treatment for Barrett oesophagus. METHODS: Histological specimens from 100 cases of Barrett oesophagus and 100 samples of normal squamous oesophageal epithelium were studied. Using a system of multiple measurements until the change in cumulative mean values varied by less than 5%, the overall mean and normal range of depth was calculated for each type of epithelium. RESULTS: Barrett columnar epithelium is minimally thicker (mean (SEM) 0.50 (0.004) mm; range 0.39 to 0.59 mm) than normal squamous epithelium (0.49 (0.003) mm; 0.42 to 0.58 mm), although this difference is probably too small to be of clinical relevance. CONCLUSIONS: Although there are numerous clinical reports of various methods of ablation treatment for Barrett oesophagus, little attention has been paid to the depth of tissue destruction required. This is the first study to look specifically at this issue, and it provides information on the necessary depth of epithelial ablation.

Virtual biopsies in Barrett's esophagus using an impedance probe.

Preliminary results of electrical impedance measurements in squamous and columnar epithelia in rat and human tissues are presented. The aim of this work is to show the possibility of differentiating these two types of epithelia in terms of their electrical characteristics. For the measurements, we employed a 1.95-m-long, 3.2-mm-diameter, four-electrode probe designed to be used transendoscopically in the diagnosis of Barrett's esophagus (BE). BE is a condition in which the normal squamous epithelium of the esophagus is replaced by columnar epithelium of the intestinal type. This metaplasia is considered as a premalignant condition that puts patients at a 30-125-fold risk of developing adenocarcinoma of the esophagus. The diagnosis and surveillance of BE involve taking multiple biopsies, an expensive and time-consuming procedure. This study constitutes the first stage in the replacement of tissue biopsy by "virtual biopsies".

Low-dose aspirin inhibits platelet and venous cyclo-oxygenase in man.

In a group of normal subjects we have compared rates of recovery of venous prostacyclin (PGI2) and platelet thromboxane B2 (TXB2) production after a single 300 mg dose of aspirin. Marked inhibition of both venous PGI2 synthesis and platelet TXB2 synthesis persisted for the 72 hours duration of the study. We also examined the effect of four daily doses of 40 mg aspirin on platelet and vessel wall prostaglandin biosynthesis. This produced a cumulative inhibitory effect on TXB2 production with 98.6 per cent mean inhibition at 72 hours. At this time 81-100 per cent inhibition of PGI2 was demonstrated in the four subjects studied. We conclude that the cyclo-oxygenase enzyme in human vein is sensitive to inhibition by very low doses of aspirin. No evidence was found to substantiate the view that rapid recovery of vessel wall cyclo-oxygenase activity occurs after inhibition by a single dose of aspirin.

Achalasia or malignancy? Confirmation of the diagnosis by oesophageal manometry.

Malignancy involving the gastro-oesophageal junction can present with features very similar to those of idiopathic achalasia. Failure to identify such cases may delay effective treatment of a curable tumour. We report four patients with malignant dysphagia who were initially referred for treatment of achalasia--the diagnosis based on clinical, radiographic and endoscopic findings in each case. In all four, oesophageal manometry suggested, correctly, that the diagnosis of achalasia was incorrect, allowing early surgical exploration. We suggest that the diagnosis of achalasia should be confirmed by manometric studies--particularly in elderly patients with a short history and weight loss as these features are frequently associated with malignancy.

The driving force in trocar insertion: a comparison between disposable and reusable trocars.

BACKGROUND: Insertion of the first trocar during the "closed" technique of creating a pneumoperitoneum remains one of the most hazardous maneuvres in laparoscopic surgery, with complications such as major vascular and bowel injuries. The ease with which trocars are inserted through the abdominal wall may have some bearing on these complications. METHODS: A range of both disposable and reusable trocars, which were identical in point cross section and size, were compared in an abdominal wall model reconstructed with animal hide, using a hand-held pressure transducer. Multiple insertions were performed, and the results were expressed in pounds per square inch (PSI). RESULTS: The disposable trocar tested required the least effort to insert (mean pressure, 2.76 PSI), followed by the new reusable (mean pressure, 3.42 PSI), with the used reusable trocar requiring the greatest force for insertion (mean pressure, 4.80 PSI). CONCLUSIONS: The effect of previous use on ease of insertion demonstrates an obvious disadvantage of reusable instruments. The excessive force required to insert some trocars may place the patient at greater risk of trocar injury.

Low frequency electrical bioimpedance for the detection of inflammation and dysplasia in Barrett's oesophagus.

Biological tissues undergoing inflammation and dysplasia seem to exhibit changes in the intercellular space that can be sensed using low frequency electrical impedance methods. Basically, low frequency electric current flows through this space and its widening as well as the disruption of the tight junction decrease the resistance, facilitating current flow. The electrical changes accompanying structural changes from columnar tissue to adenocarcinoma in Barrett's metaplastic mucosa and gastric tissue are illustrated using resected tissue from 32 patients. Two hundred and fifty-eight biopsies were analysed, correlating their electrical resistivity (R) at 9.6 kHz and their histopathological interpretation. Compared to non-inflamed non-dysplastic columnar tissue (R = 4.9 ohms m), the results suggest a small but statistically significant decrease of electrical impedance in columnar tissue showing inflammation (R = 4.2 ohms m, p = 0.016) and a larger decrease when dysplasia is present (R = 3.4 ohms m, p = 0.040). If this method is validated further, this technique could be used to obtain guided biopsies from patients undergoing surveillance programmes for Barrett's oesophagus. We aim to refine this technique using a new system with lower frequencies and, possibly, in vitro (cultured cells) and in vivo (rats) models of Barrett's oesophagus.

Assessing the conditions for in vivo electrical virtual biopsies in Barrett's oesophagus.

It has previously been shown that it is possible to differentiate between squamous and columnar epithelia in rat and resected human tissues using an impedance probe to make in vitro measurements. This probe can be passed down an endoscope allowing measurements to be made in patients. However, the probe emerges parallel to the oesophageal wall, with little room to manoeuvre. The conditions of control required to give reliable readings have been investigated. The importance of pressure applied and the angle of approach to the oesophagus was assessed. Pressures in the range 26.6 Pa to 46.3 kPa and angles in the range 15-90 degrees were considered. In in vitro studies it was observed that it was possible to obtain consistent readings with pressures greater than 2.9 kPa and with angles greater than 15 degrees between the probe and the oesophagus. These conditions can be achieved in vivo, and readings obtained from twelve patients are shown (45 readings on normal squamous, 34 on Barrett's oesophagus and 22 on stomach). At low frequencies (9.6-153.2 kHz), a Mann-Whitney test shows a significant difference (p < 0.001) when comparing the means from squamous and columnar, and also when readings from Barrett's and normal gastric epithelia are compared (p < 0.001).

Complete rectal obstruction due to ischaemia following elective abdominal aortic aneurysm surgery.

Ischaemic rectal stricture formation is a rare but documented complication of aortic aneurysm surgery. We report the first case of acute large bowel obstruction secondary to this rare complication.

Laparoscopic fundoplication for gastro-oesophageal reflux.

The initial teaching and learning experience of four surgeons performing a laparoscopic Nissen fundoplication is reported. A total of 33 patients underwent the laparoscopic approach for Nissen fundoplication. Two patients also underwent concomitant cholecystectomy. A loose 360 degrees fundoplication secured by three or four sutures was performed, with 29 patients also undergoing posterior crural repair. Three operations were converted to open procedures. Two patients required subsequent surgery, one when the fundoplication and proximal stomach slipped into the chest and one for oesophageal obstruction. No other complications occurred. All patients are well and free of reflux symptoms at follow-up ranging up to 10 months (median 5 months). Operating time ranged from 47 min to 154 min (median 81 min) for fundoplication alone. The laparoscopic fundoplications with cholecystectomy required 145 and 170 min. Postoperative stay ranged from 3 to 12 days (median 3 days). Laparoscopic Nissen fundoplication is feasible in the management of gastro-oesophageal reflux disease. These early results demonstrate that this new technique may reduce some of the morbidity associated with open antireflux surgery. A prospective randomised study has been started to assess efficacy and benefits more thoroughly.

Effect of vagotomy on the response of gastric myoelectrical activity to glucagon and food.

The myoelectrical activity of the gastric antrum was measured in 13 patients using intraluminal suction electrodes. In 3 patients with intact vagi, intravenous injection of glucagon 5 mug/kg and 10 mug/kg resulted in periods of increased frequency of gastric slow waves and also periods of inhibition. These findings persisted after highly selective vagotomy (7 patients) and were abolished by truncal vagotomy (3 patients). In each of 4 dogs, six silver/silver chloride electrodes implanted under the serosa were used to record the myoelectrical activity of the stomach and duodenum and its response to a meal of 450 gm of meat. Coordination of bursts of spike activity superimposed on the slow waves was significantly diminished after truncal vagotomy but not after highly selective vagotomy. These results confirm that changes in myoelectrical activity after vagotomy are related to the extent of vagal denervation.

Current concepts of gastrointestinal motility and electrical activity.

The motor and electrical events in the gastrointestinal tract correlate far better than do motor activity and transit of intraluminal contents. Two types of electrical phenomenon can be recorded from the smooth muscle of the bowel, namely slow waves and action potentials. Action potentials, which are superimposed on the slow waves, initiate the gastrointestinal contractions and are directly related to changes in intraluminal pressure. The characteristics of the electrical activity in the different parts of the alimentary tract are described, these being dependent on the anatomical recording site, the animal species, and the recording technique. Alterations in motility by neural and hormonal stimuli reflect the changes that these stimuli produce in the gastrointestinal myoelectrical activity.

Dilatation of benign oesophageal strictures in the outpatient department.

Maloney's mercury weighted dilators have been used to dilate benign oesophageal strictures in 109 patients in the outpatient department. A total of 524 dilatations have been performed. Following dilatation two patients had a small haematemesis but there have been no oesophageal perforations. Maloney's dilators can be used in the outpatient department effectively to dilate benign oesophageal strictures and the risk of complications is low.

Achalasia in siblings.

The occurrence of achalasia in two brothers who were successfully treated by oesophagomyotomy is reported. There was no evidence of oesophageal motor dysfunction in their parents or two other siblings who were also studied. The possibility that genetic factors may be important in the aetiology of achalasia is discussed.

Gastro-oesophageal reflux and oesophagitis before and after vagotomy for duodenal ulcer.

Fifty patients undergoing elective vagotomy for the treatment of chronic duodenal ulceration have been investigated pre-operatively and again 3 months postoperatively to determine the extent and severity of associated gastro-oesophageal reflux. Pre-operatively all patients had a normal lower oesophageal sphincter pressure but 50 per cent had symptoms of gastro-oesophageal reflux, 42 per cent had excessive reflux on 24 h pH monitoring and 30 per cent had oesophagitis on endoscopy and/or oesophageal biopsy. Postoperatively, reflux symptoms were present in only 12 per cent of patients but pH studies were still abnormal in 36 per cent and oesophagitis was observed in 32 per cent. Lower oesophageal sphincter pressure was unaffected by vagotomy. Gastro-oesophageal reflux is common in pre-operative duodenal ulcer patients and is not significantly reduced by vagotomy. Careful pre-operative oesophageal assessment is necessary to determine which duodenal ulcer patients require an anti-reflux procedure in addition to vagotomy.