Moran repair for inguinal hernias.

A total of 1282 inguinal hernia repairs were performed between September 1989 and June 1994 using polypropylene mesh inserted in the preperitoneal space to reinforce a two-layer transversalis fascia technique. There was a recurrence rate of 0.4 per cent with a minimal follow-up of 14 months. All the operations were performed as outpatient surgery, under local anesthesia or general anesthesia, with immediate ambulating home and early return to normal activities and work. Complications were minimal, with no mortality.

Biopsy problems in patients with musculoskeletal tumours.

The problems of biopsy procedures and the effect that these had on subsequent surgery were studied in fifty one consecutive patients with musculoskeletal tumours. Difficulties included inadequate tissue for histology in 4 patients, wound infection in 5, haematoma formation in 2, inappropriate biopsy site in 7 and incorrect placement of drain exit site in 4. Open biopsy gave a more reliable diagnosis than needle biopsy, but was associated with a higher incidence of complications. Staging techniques such as magnetic resonance imaging, computed tomography and bone scans were less accurate when performed after the biopsy. Longitudinal incisions, centred over representative tumour tissue with the drain site placed in line with the incision, facilitate the adequate and uncomplicated removal of the entire biopsy scar and tract at the time of the definitive surgical procedure. It is concluded that biopsy for suspected musculoskeletal tumours should not be delegated to junior residents and should be performed in centres that have experience in the management of such tumours.

Ascitic pseudocyst obstructing superior vena cava as a complication of a peritoneo-venous shunt.

A pseudocystic mass obstructing the superior vena cava is described as a complication of a LeVeen peritoneo-venous shunt. This unusual complication is thought to result from a foreign body reaction to the tubing in conjunction with the low flow though the tubing.

Antihypertensive and hemodynamic actions of SCH 19927, the R,R-isomer and labetalol.

SCH 19927, one of the four chiral forms of labetalol, is approximately 4 times as potent as a beta adrenergic receptor blocker as the parent racemate, but is only one-third as potent in blocking alpha receptors. The present report describes its antihypertensive and hemodynamic actions. SCH 19927 and labetalol lowered blood pressure in hypertensive rats and dogs. SCH 19927 was somewhat more effective at lower doses, but the two agents produced comparable responses at higher doses. Both reduced blood pressure and peripheral resistance and increased cardiac output in anesthetized dogs. Intraarterial injection in to the femoral vascular bed, either in the presence or absence of neurogenic vasoconstrictor tone, resulted in dose-related vasodilatation. In contrast, alpha blockers, e.g., phentolamine and prazosin, are essentially devoid of vasodilator activity in denervated beds. It is concluded that vasodilatation is largely responsible for the antihypertensive response to labetalol and particularly to SCH 19927. SCH 19927 is a potentially useful agent which would be expected to reduce pressure in humans by two complementary mechanisms, beta blockade and vasodilatation. It should possess less orthostatic potential than labetalol.

Comparison of hypotensive, orthostatic and sympathetic inhibitory actions of antihypertensive drugs in rats.

Hypotensive and orthostatic activities of a variety of orally administered antihypertensive drugs were concurrently evaluated in conscious spontaneously hypertensive rats and attempts were made to relate these responses to effects on peripheral sympathetic function. The alpha-adrenergic blockers phentolamine and prazosin and the adrenergic neuron blocker guanethidine inhibited compensatory responses to upright tilt at antihypertensive doses. The ganglionic blocker mecamylamine produced milder inhibition. The centrally active agents methyldopa and clonidine and the vasodilator minoxidil did not alter tilt responses appreciably. In contrast, the vasodilator hydralazine exerted marked postural effects. Autonomic interactions were evaluated in pithed rats. alpha-Adrenergic receptor, adrenergic neuron and ganglionic blockers inhibited pressor responses to i.v. phenylephrine and/or to sympathetic nerve activation. Vasodilators did not produce specific effects. The tilt and pithed rat models, when used in conjunction, are very useful in predicting orthostatic potential of drugs in humans although absolute correlation cannot be expected.