Traumatic pseudoaneurysm of the superficial temporal artery associated with facial nerve palsy.

Aneurysms of the superficial temporal artery as a result of trauma occur rarely. These pseudoaneurysms tend to present 2 to 6 weeks following initial injury with a painless swelling which may be associated with a headache, ear discomfort or other vague symptoms. Neurological complications are very rare. A thorough history and physical examination are essential. Investigations such as duplex scanning, angiography or CT scanning may be helpful in difficult cases. The most common treatment is surgical. Embolization may prove to be an alternative to surgery in some cases. We review a rare case of superficial temporal artery aneurysm associated with a facial nerve palsy which was treated surgically. A thorough review of the literature is presented.

Is laparoscopy associated with a lower rate of postoperative adhesions than laparotomy? A comparative study in the rabbit.

This trial set out to test the hypothesis that there is no difference in the incidence of intra-abdominal adhesions after a stereotyped intraperitoneal injury created via laparoscopy or laparotomy. Twenty New Zealand White rabbits had a 2 x 2 cm area of peritoneum stripped off their caecum and adjacent parietal peritoneum, either by laparotomy or laparoscopy. Outcome was assessed by the incidence of adhesions to the test site and the wound. There was no difference in the rate of adhesions at the test site in the two groups. The rate of adhesions to the wound was different in the two groups (70% laparotomy, 0% laparoscopy; P = 0.003). In a rabbit model, comparing laparoscopy and laparotomy in a strictly controlled operative environment, a stereotyped intraperitoneal injury results in similar rates of postoperative adhesions. Laparoscopy is, however, associated with a much lower incidence of wound adhesion. The potential for postoperative adhesions is real after laparoscopic surgery.

Duplex scan surveillance of infrainguinal prosthetic bypass grafts.

PURPOSE: Surveillance protocols of infrainguinal vein bypass grafts have almost universal acceptance. To date corresponding studies of prosthetic grafts have not been carried out. We have performed a prospective 4-year duplex scan follow-up on polytetrafluoroethylene grafts to assess the usefulness of a surveillance program of prosthetic bypass grafts in preventing graft failure. METHODS: Over 4 years 69 infrainguinal polytetrafluoroethylene grafts in 56 patients were studied at six monthly intervals by our vascular laboratory. Full duplex scan mapping of the grafts and inflow and outflow arteries and standard ankle pressure measurements were performed. A midgraft peak flow velocity was also measured. RESULTS: Over 4 years 27 (39.1%) grafts occluded without any predictive changes in the preceding duplex scan examination. Of the 42 (60.9%) grafts that remained patent, only four developed stenoses (three at the proximal anastomosis and one at the distal anastomosis) that were amenable to intervention. Changes in ankle pressures or midgraft flow velocity did not predict failure. CONCLUSIONS: The low yield of remediable disease does not justify the cost of duplex scan surveillance of infrainguinal prosthetic bypass grafts.

Venous stasis during laparoscopic cholecystectomy.

The objectives of this research were (a) to determine the effect of insufflation at laparoscopic cholecystectomy to 12 mm Hg on femoral venous blood flow; and (b) to assess the function of intermittent pneumatic compressors (IPC) and intermittent electric calf stimulators (IECS) in the presence of a pneumoperitoneum. Measures of baseline venous blood flow velocity, femoral vein diameter, and maximum blood flow velocity achieved by IPC or IECS were made in the presence or absence of a pneumoperitoneum of 12 mm Hg. The ICP and IECS were randomly allocated to either leg. All measures were made by an experienced sonologist. Insufflation to 12 mm Hg caused a statically significant decrease in femoral blood flow velocity and was accompanied by a significant increase in femoral vein diameter. The IPC and IECS were able to achieve pulsatile venous blood flow despite the presence of a pneumoperitoneum, but they had no effect on the depressed baseline blood flow velocity. We concluded that insufflation to 12 mm Hg causes significant venous stasis in the lower limb and that IPC and IECS cannot completely eliminate this stasis. Further research needs to be done to clarify the optimal methods of prophylaxis in view of the implications for deep venous thrombosis.

Lower limb venous hemodynamics during laparoscopy: an animal study.

To assess the impact of raised intra-abdominal pressure associated with laparoscopy on venous return, we have used an animal model (pig) to study the effect of progressive increases in insufflation pressure on femoral venous blood outflow. As a second variable, the effect on flow of the reverse Trendelenburg position was also assessed. Evidence of any adaptation in venous blood flow to the increased intra-abdominal pressure was assessed during a prolonged surgical procedure. These studies have shown that femoral venous blood outflow in the pig is markedly depressed at insufflation pressures of 10 to 20 mm Hg. The reverse Trendelenburg position accentuates this reduction in flow, and there was no sign of adaptation to this depressed flow during a laparoscopic Nissen fundoplication. These findings have clear implications for the potential of deep venous thrombosis/pulmonary embolism (DVT/PE) following prolonged therapeutic laparoscopy.

Azithromycin clinical pharmacokinetics.

Azalide antibiotics, of which azithromycin is the first demonstrated, have different pharmacokinetics from other antibiotics currently used. The bioavailability of the drug is approximately 37%. Extensive and rapid distribution from serum into the intracellular compartments is followed by rapid distribution to the tissues. Tissue concentrations exceed serum concentrations by up to 100-fold following a single azithromycin 500mg dose. Concentration of the drug within phagocytes aids in its ability to combat infections. High concentrations of azithromycin are found in the tonsil, lung, prostate, lymph nodes and liver, with only small concentrations found in fat and muscle. A 500mg dose on day 1, followed by 250mg daily on days 2 to 5, has been demonstrated to maintain azithromycin concentrations at sites of infection and continues to be effective for several days after administration has ceased. The pharmacokinetics of azithromycin make it a drug with diverse therapeutic applications.