The propensity of pleomorphic adenomas to recur is generally attributed to the biological nature of the tumour, and surgery close to the capsule is perceived as undesirable. At the Christie Hospital, Manchester, between 1947 and 1992, 475 tumours arising within the superficial portion of the parotid gland were treated by two surgical techniques: extracapsular dissection (380 patients) and superficial parotidectomy (95). Recurrence rates were 2 per cent in each group (median follow-up 12.5 years). Contact of the tumour with the facial nerve was recorded in 51 per cent of patients. There was no difference between the treatment groups in the incidence of permanent facial nerve injury (2 versus 1 per cent respectively). This study demonstrates that dissection in close proximity to the tumour is possible without inducing recurrence and that in practice the microinvasion of the capsule by tumour buds has limited clinical significance.

Between 1947 and 1992, 1403 patients with 1432 salivary gland tumours were treated at the Christie Hospital, Manchester. There were 1194 epithelial neoplasms: parotid, 1082 (91 per cent); submandibular, 47 (4 per cent); minor glands, 65 (5 per cent). The commonest histological diagnoses were pleomorphic adenoma (n = 776) and adenolymphoma (n = 159). A total of 244 carcinomas were seen (adenoid cystic carcinoma, n = 75). Treatment was primarily surgical, conservative where possible, and determined by tumour extent and not histology. Adjuvant radiation therapy was used in over half the definitively treated malignancies. The recurrence rate following the treatment of 551 new parotid pleomorphic adenomas was 1.6 per cent at median follow-up 12.5 (range 1-34) years, increasing to 15 per cent in the secondarily referred group (n = 170). For patients with definitively treated primary salivary carcinomas (n = 148), the disease-free survival rate at 5, 10 and 15 years was 58, 47 and 45 per cent respectively. Using multivariate analysis, clinical stage was the most important predictor of survival; the 10-year survival rate for stages I-IV was 96, 70, 47 and 19 per cent respectively.

SUMMARY A fine open perfused system and a closed balloon system for the measurement of anal pressure and motility have been compared. Measurements were made in 40 normal subjects and 84 patients with haemorrhoids. The rate of perfusion had a marked effect on the recorded pressure and motility details. The motility pattern was seen most clearly with the balloon probe and the pressure recorded was reproducible and easy to measure, making this a convenient method for recording activity of the internal anal sphincter. Anal motility in normal subjects was characterised by slow pressure waves (10-20/min). The frequencywasfastestinthedistal analcanalandthisfrequencygradient may represent a normal mechanism to keep the anal canal empty. Ultra slow pressure waves (0-6-1 9/ min) were seen in 42 % of patients with haemorrhoids and 5 % of normal subjects and arose from a synchronous contraction of the whole internal sphincter.

SUMMARY Internal anal sphincter activity has been studied in 84 patients with haemorrhoids and 40 asymptomatic subjects. Activity was estimated by measuring maximum resting anal pressure with a water filled anal balloon probe 7 mm in diameter connected to a strain gauge pressure transducer. There was greater activity of the internal sphincter in patients with haemorrhoids than in controls, but there was no significant relationship between sphincter activity and duration of symptoms, predominant symptom (bleeding or prolapse), severity of symptoms, history of pain, history of straining at stool, or size of haemorrhoids. Straining at stool occurred significantly more often in patients whose main complaint was prolapse than in those whose main complaint was bleeding. Anal dilatation reduced sphincter activity and the best clinical results were obtained in those with the most active sphincter. An internal sphincter abnormality may be an aetiological factor in some patients but there must be other factors as well. Straining at stool may determine whether bleeding or prolapse is the predominant symptom.The internal sphincter is overactive in some patients with haemorrhoids (Kerremans, 1969;Hancock and Smith, 1975). This is in evidence by an increased resting anal pressure and the presence of ultra slow pressure waves (0-6-1 9/min). This activity when present is abolished by anal dilatation (Hancock and Smith, 1975) with relief of symptoms, so it seems possible that a sphincter abnormality is related to the development of symptoms in patients with haemorrhoids.The clinical picture produced by haemorrhoids is very variable, and, in order to investigate this possible relationship, an attempt was made to correlate internal sphincter function with symptoms and appearances in series of patients with haemorrhoids. MethodsAnal pressure and motility were measured with an anal probe consisting of a small balloon built into a hollow Perspex rod of 7 mm diameter (Fig. 1). The balloon was filled with water and inflated to produce a slight convexity of its surface and was connected via fine polyethylene tubing to a Statham strain gauge pressure transducer. This in turn was connected to a Devices multichannel recording machine and the tracings were produced on heat sensitive paper.Received for publication 20 December 1976 The recording was taken without bowel preparation and before any examination. The recording was taken with the probe at centimetre steps from the anal verge and lasted about 15 minutes and the average pressure at each position in the anal canal was estimated with reference to a calibration of 100 cm H20 (Fig. 2). The resting pressure was often steady (Fig. 3), but sometimes regular pressure waves of long frequency and high amplitude were seen. If these pressure waves had a frequency of less than 2/min and an amplitude greater than 25 cm H20 they were called ultra slow waves (Fig. 3). It has been shown previously that ultra slow waves persist under anaesthesia with the external sphincter paralysed and are associa...

Anal pressure and motility have been measured in 56 patients with haemorrhoids and 40 asymptomatic subjects. The anal pressure of patients with haemorrhoids (93-6 cm H2O) was very significantly higher than that of the controls (66-8 cm H2O; P less than 0-001). Ultra-slow pressure waves (amplitude 25-100 cm H2O, frequency 0-9-1-6/min) were present in 39 per cent of patients with haemorrhoids, but in only 7-5 per cent of the controls (P less than 0-001). Ultra-slow waves are present under anaesthesia with the voluntary muscles paralysed and are associated with the highest anal pressure, and so, represent abnormal activity of the internal anal sphincter. Measurements after anal dilatation showed complete abolition of ultra-slow wave activity and a very significant drop in pressure. One year after dilatation 19 patients had a mean anal pressure of 62 cm H2O. Very good results were obtained unless the haemorrhoids were so large that they prolapsed at times other than defaecation. Lord's procedure is a rational treatment since it corrects an underlying overactivity of the internal sphincter.