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PURPOSE: The subgroup of patients with venous ulcers requiring anticoagulation for co-morbid conditions has traditionally created a therapeutic dilemma. Perioperative management of anticoagulation can be costly and increase the risk of surgical complications. This group of patients is often elderly and shows poor compliance with compression hosiery. The aim of this study was to investigate the outcome of endovenous laser ablation (EVLA) of the great saphenous vein (GSV) in patients remaining on therapeutic anticoagulation. MATERIALS AND METHODS: Fifteen consecutive patients (CEAP [clinical, aetiological, anatomical and pathological elements] classification 5 or 6) were treated with standard GSV EVLA using tumescent anaesthesia and a diode 1470-nm radial laser fibre while maintaining international normalized ratio at therapeutic levels. Clinical and duplex follow-up at six weeks and three, six and 12 months were performed. RESULTS: The GSV was successfully occluded in 14/15 (93%) of patients. The remaining patient had a second successful treatment three months later. No significant complications requiring intervention were encountered. CONCLUSION: EVLA using the diode 1470-nm radial fibre is efficacious with minimal complications in patients therapeutically anticoagulated. This treatment should be added to the armamentarium in this problematic patient group.

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OBJECTIVE: To perform a more critical assessment of infrainguinal vein bypass. SUMMARY BACKGROUND DATA: Graft patency may give an unrealistic impression of the outcome of bypass surgery. METHODS: During a 6-year period, 236 patients undergoing primary vein grafts were entered into the study. An ideal outcome required the patient to have survived 12 months with a patent graft on duplex scanning, no perioperative complication, and no further related open or endovascular surgery or admission. RESULTS: At 12 months, the secondary graft patency rate was 82%; however, only 22% of patients had an ideal outcome. At 1 year, 44 (19%) patients died, 93 (39%) required further ipsilateral and 39 (17%) contralateral intervention, and a total of 108 (46%) were readmitted. An ideal outcome was more likely in patients receiving calcium channel blockers, principally because of improved primary patency, and less likely in those with cardiac failure requiring furosemide, principally because of worse survival in these patients. CONCLUSIONS: Few patients achieve an ideal result after infrainguinal vein bypass. Outcome may be improved by the use of calcium channel blockers. Careful consideration is required before performing revascularization in patients with cardiac failure.

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In an attempt to predict early graft occlusion secondary to poor distal run-off, the outflow resistance was measured intra-operatively and compared with the intra-operative angiogram in 50 patients undergoing lower limb bypass procedures. With arterial inflow occluded, 60 mL of plasmalyte was infused via a catheter and the resultant pressure generated in the graft was measured through a second catheter connected to a pressure transducer and recorder. Using the infusion rate and integrated pressure value, outflow resistance was calculated. High resistance measurements were defined as grafts with outflow resistance greater than 1.1 mmHg/mL per min, low measurements were defined as values less than 0.5 mmHg/mL per min and intermediate measurements were those in the range 0.5-1.1 mmHg/mL per min. Angiograms were classified independently of resistance measurements by scoring the numbers of run-off vessels crossing the ankle and stenoses, with subsequent assignment of the patient to one of three groups with either low, intermediate, or high probability of graft failure. Early graft failure was defined as cessation of graft function within 3 months of surgery. Early graft failure occurred in both cases with high outflow resistance and in seven of 44 with low outflow resistance. Of these nine occluded bypasses, six had been placed in the high probability of occlusion category on angiographic appearance and three in the intermediate category. Assessment of angiographic appearance and prediction of patency on a prospective basis had a sensitivity rate of 67% and a specificity rate of 78%. The corresponding sensitivity and specificity rates with resistance measurements were 22% and 100%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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The effects of cholecystokinin octapeptide (CCK-OP) on the gall-bladder (GB) and sphincter of Oddi (SO) of the Australian brush tailed possum were examined in 45 anaesthetized animals. CCK-OP (20-640 ng/kg) consistently caused the GB to contract in a dose-dependent manner (Kruskal Wallis P less than 0.05). In 20 animals, the same dose range of CCK-OP produced an excitatory response in the SO, increasing the SO motility index (MI = frequency of contractions x mean peak amplitude) dose-dependently (Kruskal Wallis P less than 0.05). In five animals, an inhibitory response, that is, a decrease in MI, was recorded, with 640 ng/kg of CCK-OP producing a 50% decrease in MI. In the remaining 20 animals, variable responses of both excitation and inhibition were elicited within the same animal. The action of CCK-OP on the SO and GB was not modified by atropine, phentolamine or propranolol. Tetrodotoxin (TTX) reversed the inhibitory responses of the SO to CCK-OP such that responses were excitatory (sign test P less than 0.05). TTX did not alter the response of the GB to CCK-OP. It is concluded that CCK-OP acts directly on smooth muscle receptors of the GB. In the SO, its action is mediated via non-cholinergic, non-noradrenergic inhibitory neurons and also by a direct excitatory action on the smooth muscle of the SO.

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Sphincter of Oddi motility was evaluated in post-cholecystectomy patients with indwelling T tubes during fasting and after feeding. A triple-lumen catheter was positioned to record from the sphincter of Oddi and duodenum. The sphincter of Oddi was characterized by phasic contractions independent of duodenal contractions. During fasting duodenal wave frequency exhibited four phases, whereas only two phases could be identified from the sphincter of Oddi. A prolonged phase A in the sphincter of Oddi corresponded to duodenal phases I, II and IV. A short phase B in the sphincter of Oddi just preceded the onset of duodenal phase III and was temporally related to it. Sphincter of Oddi basal pressure increased during duodenal phases III and IV. After ingestion of food, sphincter of Oddi basal pressure, wave amplitude and duration decreased, but the frequency remained unchanged. Conversely, duodenal frequency increased but there was no change in amplitude. Thus, the human sphincter of Oddi and duodenum exhibited independent motility demonstrating distinct phases during the interdigestive period. After food, sphincter of Oddi motility altered in a manner which would facilitate the passive flow of fluid into the duodenum.

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Intraluminal pressure recordings from the sphincter of Oddi (SO) have made significant contributions towards the understanding of normal SO function and are being used for the diagnosis of SO motility abnormalities. In this study the endoscopic intraluminal methods for measuring SO pressure changes have been adapted for use under sterile conditions during surgery on the biliary system. Sphincter of Oddi pressure measurement in a group of patients undergoing elective cholecystectomy for gallstones, were compared with a group of control subjects undergoing endoscopic study of the SO. There was no significant difference in CBD pressure. SO basal pressure, SO wave amplitude and SO wave frequency. However, a highly significant difference was noted in the propagation direction of the SO contractions. The control subjects had a predominance of antegrade contractions whereas patients undergoing cholecystectomy had a predominance of retrograde contractions. This result suggests an association between SO motility disorder and the presence of gallstones.

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Animal studies have shown that the gallbladder (GB) empties partially during fasting in relation to phase II of the interdigestive motor cycle (IDMC). It has been assumed that in man the GB remains inert during fasting, although there have been no studies in which repeated sequential measurements of gallbladder volume have been made and related to the IDMC. In this study the possibility of linkage between the IDMC and GB volume has been examined in nine fasting human volunteers (five males/four females). A multilumen constantly perfused manometry catheter was positioned in the duodenum and motor activity recorded continuously. Phase III of the IDMC was characterized by phasic contractions, with a frequency of 10-12/min for at least 2 min, which had a distal propagative pattern and were followed by a motor quiescence (Phase I). GB volume was calculated at 15 min intervals from ultrasound measurements of the maximal length and diameter of the GB by the summation of cylinders method, and related to the time of onset of each phase III of the IDMC. In all nine subjects GB volume decreased prior to the onset of phase III and increased following its passage (P less than 0.01). GB volume decrease ranged between 6 and 56% of maximal GB volume (median 18%) and subsequent filling ranged from 14 to 53% (median 27%). The maximal volume decrease occurred 30 min prior to the onset of phase III (P less than 0.02). These studies have demonstrated that the human GB empties partially during phase II of the IDMC.(ABSTRACT TRUNCATED AT 250 WORDS)

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Massively obese patients are at high risk for developing cholesterol gallstones. The objectives of this study were to determine the influence of massive obesity on the cholesterol saturation of bile, and to examine the effect of massive obesity on the ability of chenodeoxycholic acid to decrease biliary cholesterol saturation. Gallbladder bile collected at surgery from massively obese patients was significantly more saturated with cholesterol than bile from non-obese patients who were matched for age, sex and gallstone status (P less than 0.01). Median biliary cholesterol saturation index values for groups of subjects were: no gallstones-not obese (0.83); no gallstones-obese (1.14); gallstones-not obese (1.08); gallstones-obese (1.37). Furthermore, a 5-week course of chenodeoxycholic acid (6 mg/kg/day) was less effective in reducing biliary cholesterol saturation in massively obese patients. The bile of 4 of 10 obese patients remained supersaturated, compared to only one of 10 non-obese patients. These results indicate that biliary cholesterol saturation is raised in massive obesity and that in this condition, the biliary lipid response to chenodeoxycholic acid is diminished. This may explain why obese patients have a relatively poor response to gallstone dissolution therapy with this bile acid.

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1. A method is described for altering the pressure across the wall of the carotid sinus in conscious rabbits by enclosing the carotid bifurcation in a rigid, fluid-filled capsule. The extracapsular arterial baroreceptors were denervated. 2. The baroreceptor--heart rate reflex, elicited by injecting vasoactive drugs or inflating aortic and vena caval cuffs, was used to test the new method. The function of the carotid sinus was shown to be unaffected by enclosure in the capsule. Denervation of the extracapsular baroreceptors reduced the gain of the baroreceptor--heart rate reflex two- to threefold. 3. The characteristics of the carotid baroreceptor reflex were studied in sixteen animals by the capsule method. Median estimates of maximum gain, and the range over which blood pressure changed, were 1.1 mmHg/mmHg and 57 mmHg respectively. There was good agreement between duplicate estimates made 1--20 days apart. 4. There was only a weak association between the effects on blood pressure and heart rate of altering carotid sinus transmural pressure. Autonomic blockade of the heart, so that its rate was fixed, did not reduce the gain or range of blood pressure change.

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1. The change in arterial pressure and heart rate resulting from alteration of carotid sinus transmural pressure by a median--34 mmHg and +33 mmHg by means of a variable-pressure neck chamber was tested in seven male volunteer subjects, at rest and during exertion of 35, 45 and 65% of maximum voluntary handgrip. 2. During 60 s of 35 and 45%, and during 30 s of 65%, of maximal voluntary handgrip there was virtually no alteration of the response of blood pressure to alteration carotid sinus transmural pressure. 3. The bradycardic response to increase in carotid sinus transmural pressure was reduced at various times after the commencement of handgrip at 45 and 65% of maximum voluntary contraction. 4. It is concluded that a reduction in arterial baroreceptor reflex sensitivy does not play an important role in the initiation of the increase in arterial blood pressure and heart rate caused by isometric exercise. 5. The hypothesis is advanced that some of the cardiovascular changes in exercise may result from elevation of the central 'set point' for blood pressure.

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1. The changes in R--R heart interval that result from step-increase and step-decrease in carotid sinus transmural pressure induced by a variable pressure neck chamber were measured in seven normal men. Observations were made at rest, and during isometric hand-grip exercise at 24%, 44% and 64% of maximal voluntary contraction. 2. The response of heart interval to increase in carotid sinus transmural pressure was progressively and markedly diminished according to the strength of hand-grip. This effect was fully developed from the moment of onset of the exertion. 3. The response of heart interval to decrease in carotid sinus transmural pressure was much less consistently affected by hand-grip exercise.

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