Biomedical subjects
H L Duthie
Publications and source records attributed to H L Duthie.
Highly selective vagotomy or truncal vagotomy and pyloroplasty for chronic duodenal ulceration: a randomized, prospective clinical study.
The results of a randomized, prospective clinical trial of highly selective vagotomy (HSV) versus truncal vagotomy and pyloroplasty (TVP) in 126 male patients undergoing elective surgery for chronic duodenal ulceration are presented. The operations were performed by surgeons of all grades of experience. At a mean follow-up time of just over 3 years a satisfactory result was obtained in 93 per cent of patients following HSV and 78 per cent of patients following TVP, the difference being probably statistically significant (P less than 0.05). The incidence of early and late dumping, bile vomiting, flatulence, post-prandial epigastric discomfort and wound infection was statistically significantly less after HSV than after TVP. Three patients have developed a recurrent duodenal ulcer after each type of operation (5.4 per cent). At this early stage HSV has advantages over TVP; it will be interesting to see if these are maintained with the passage of time.
Electrical activity of human colonic smooth muscle in vitro.
1. Extracellular and intracellular recordings were made of the electrical activity of isolated strips of human colonic smooth muscle, cut from sixty surgical specimens. 2. Strips of taenia were spontaneously active. The myogenic activity consisted in half the strips of intermittent periods of regular spike activity (frequency 22 +/- 5 (S.D.) c/min) accompanied by tetanic contractions; in the other half of the strips activity was continuous. In half the specimens, slow potentials were recorded between periods of spike activity. Slow potentials were not accompanied by contractions. 3. Spikes in taenia were abolished by verapamil. Spikes disappeared in low Ca and low Na solutions, but in low Na solution spikes could be stimulated by 15 mM-KCl. 4. ACh and physotigmine produced tetanic contractions in taenia. 5. Circular muscle was not spontaneously active within 1 h of incubation in the water bath, possibly due to inhibition by prostaglandins. 6. Circular muscle responded to ACh with irregular bursts of spikes associated with discrete contractions. Similar activity was seen after inhibition of prostaglandin synthesis with indomethacin. After treatment with tetrodotoxin, ACh produced regular spikes and tetanic contractions in circular muscle. 7. The possible relationships of these results to the myoelectrical activity of the human colon in vivo are discussed.
Abdominal wound healing: a prospective clinical study.
The incidence of wound dehiscence and incisional hernia after two methods of abdominal wound closure (layered closure with retention sutures and single-layer "mass closure") was studied in a randomised prospective clinical trial in a consecutive series of 200 patients. Dehiscence occurred in 1% of patients and herniation in 4-7%; the incidence of these complications was similar with both methods of closure. Seven of the 11 cases of dehiscence or herniation occurred in infected wounds, and wound infection was associated with a tenfold increase in the incidence of these complications. The prevention of wound infection would reduce substantially the incidence of dehiscence and herniation in abdominal wounds.
Surgery for gastric ulcer.
Despite the initial healing achieved by medical treatment with carbenoxolone, surgery is frequently needed in the management of gastric ulcer. We have studied 150 patients over the past 10 years in an attempt to define the place of conservative surgery compared with the standard partial gastrectomy of the Billroth I type. Functional results have not been significantly different and the individual surgeon's choice will depend on his philosophy with regard to the risk of cancer in the postoperative stomach, and his technical expertise with the newer kinds of vagotomy. To my mind it is perfectly justifiable to use highly selective vagotomy with excision of the ulcer to treat gastric ulcer alone, especially if the patient is one in whom postgastrectomy symptoms could be disabling. Further follow-up is needed to decide whether it should replace partial gastrectomy as the standard procedure.
Brainstem neurones sending efferent fibres to the abdominal viscera of the dog [proceedings].
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Bran tablets and diverticular disease.
Three treatments for patients with symptomatic diverticular disease were compared in a crossover trial. Neither a high-roughage diet (HRD) nor Normacol plus an antispasmodic were as effective as bran tablets, which produced a significant increase in daily stool weight and a decrease in the intestinal transit time. An abnormal rapid electrical rhythm in colonic smooth muscle was found initially in 80% of the patients, but the incidence was reduced by each treatment after one month; it was present in only 40% of patients after treatment with bran tablets. Only bran significantly reduced a high percentage motility to within normal limits. Bran proved to be the most effective treatment, not only in improving the symptoms in patients with diverticular disease but also in returning to normal the abnormal pathophysiological changes. Bran tablets were both convenient and acceptable as well as effective.
Layer closure of laparotomy wounds with absorbable and non-absorbable suture materials.
Opinions vary regarding the best suture material for abdominal wound closure. Some surgeons favour non-absorbable sutures while others use absorbable materials, but there is little objective clinical information regarding the relative merits of the different suture materials. In a randomized prospective clinical trial the synthetic absorbable polyglactin and polyglycolic acid sutures were compared with the non-absorbable polypropylene suture in the closure of 161 laparotomy wounds. A layered closure technique was used in all cases. The total incidence of wound dehiscence and herniation was 8-1 per cent, and there was no significant difference between polylycolic acid (9-6 per cent), polyglactin (5-8 per cent) and polypropylene (8-8 per cent). Dehiscence and herniation were significantly more common in wounds closed by surgeons in training. It was concluded that none of the suture materials provided satisfactory freedom from wound complications. It is possible that these sutures may prove satisfactory with an alternative technique of abdominal wound closure, but this should be the subject of further clinical studies.
Mathematical modeling of the colorectal myoelectrical activity in humans.
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Gastric emptying in control subjects and patients with duodenal ulcer before and after vagotomy.
The emptying of a solid meal labelled with Indium 113mDTPA from the stomach was studied with a gamma camera in 26 normal subjects, 27 patients with duodenal ulcer, on 41 occasions after truncal vagotomy and pyloroplasty and 38 times after highly selective vagotomy. Applying the method of principal component analysis to the results, differences were detected between control and duodenal ulcer subjects and two probable subgroups of duodenal ulcer were observed. Half emptying times did not reveal these patterns. After vagotomy, delayed emptying was general at one week. At one month, patients after highly selective vagotomy had a more normal result than those with truncal vagotomy and pyloroplasty (TV), but by six months no significant difference in overall emptying rate was found, although changes in the pattern of gastric emptying persisted in some patients after TV.
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.
Proceedings: Bran tablets in the treatment of diverticular disease.
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Intestinal smooth muscle electrical potentials recorded from surface electrodes.
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Large bowel myoelectrical activity in man.
The myoelectrical activity of human colon and rectum has been studied by three types of electrode in man--intraluminal (suction), serosal and cutaneous. The patterns obtained indicate a high degree of consistency between the methods and the value of surface electrodes is emphasized. Gradient along the large bowel of both frequency and percentage electrical activity have been observed and possible physiological roles are postulated for them. By correlating the features of regular electrical and corresponding regular motor waves an alteration in the myoelectrical pattern is observed in the region of the rectosigmoid junction.
Glucagon and the colon.
The effect of glucagon on human colonic myoelectrical activity is described. By means of intraluminal, serosal, and surface electrodes, recordings from all areas of the large bowel have been obtained. Glucagon inhibited both electrical and pressure rhythms in all subjects tested. Evidence is produced to suggest a direct action on colonic smooth muscle. A controlled trial using glucagon during routine barium enema examinations suggests that it may prove to be useful for hypotonic examinations of the colon where painful spasm is present.
The immediate and delayed effects of different types of vagotomy on human gastric myoelectrical activity.
The immediate and delayed effects of different types of vagotomy on the antral myoelectrical activity have been studied in 52 patients who had previously undergone either highly selective vagotomy (HSV) or truncal vagotomy and pyloroplasty (TV + P) for the treatment of chronic duodenal ulceration up to eight years previously. The frequency of the electrical activity was not statistically different between the two types of operation. After HSV the triphasic waveshape of the antral myoelectrical activity was retained; it was recorded more frequently in the delayed tests (98.0 plus or minus 1-7%) of the recording period than in immediate tests (74-7 plus or minus 6-5%) whereas mean amplitude in the immediate tests (1-59 plus or minus 0-13 mV) was not significantly changed in the delayed tests (1-49 plus or minus 0-08mV). After TV + P the waveform was more sinusoidal in shape, being recorded more often in the delayed tests (91-7 plus or minus 2-7%) than in the immediate tests (41-4 plus or minus 8-9%) although the mean amplitude between the immediate (0-090 plus or minus 0-06 mV) and delayed tests (0-94 plus or minus 0-07 mV) was not significantly different. The only significant change in the myoelectrical activity with the passage of time after vagotomy was an increase in the percentage activity.
A linked oscillator model of electrical activity of human small intestine.
The electrical slow-wave activity of the human small intestine has been simulated by a chain of 64 coupled electronic relaxation oscillators. The model simulates the frequency gradient of recorded patoentials in the human small intestine and when transected, behaves in a similar way to the transected canine small intestine. The model exhibits a spontaneous effect whereby several adjacent oscillators periodically are in the same state. This effect travels down the model in the time of 20-30 min.