w e have shown previously (Couvreur et a1 1977) that polyacrylamide nanocapsules are a new type of lysosomotropic carrier, but unfortunately they are unlikely to be digested by lysosomal enzymes. This article describes the preparation and the morphology of polyalkylcyanoacrylate nanocapsules since polyaanoacrylate may be biodegradable, as suggested by its us in surgery (Collins et al 1969;Heisterkamp et al 1969) and by its chemical properties (Cameron et al 1965; Leonard et a1 1966 a, b; Pani et al 1968).We also present results of the sorption of small molecules on these nanocapsules.f Correspondence. b. 1. Morphological appearance of polymethyl-VUoacrylate nanocapsules by scanning electron -0scopy.Polymethyl and polyethylcyanoacrylate nanocapsules were prepared by polymerization. To Tween 20 (0.25 g), HCI 0.1 M (5.0 ml) in distilled water (50.0 ml) was added 0.6 ml of either of the monomers (methyl-or-ethylcyanoacrylate). After mechanically stirring for 30 min the mixture was passed through a fritted glass filter (pore size 9-15 pm) and then distilled water added t o 200 ml. After preparation, nanocapsules form milky suspensions displaying a Tyndall effect. The particles pass through a Millipore filter with 0.45 pm pores. This method is rapid and easy and avoids the destructive y-irradiation used in the preparation of polyacrylamide nanocapsules (Couvreur et al 1977).Scanning electron microscopy shows spherical particles with a diameter of about 200nm (Fig. 1). Variation of the Tween 20 concentrations did not affect the morphological appearance and size. Particles obtained without surfactant seem to be more agglomerated and larger than those with surfactant.Suspension of nanocapsules prepared with Tween 20 (0.1%) were spray frozen (Bachmann & SchmittFumian 1973) and examined by the electron microscope after freeze fracture. The use of fixatives and cryoprotectants are avoided by this method, while surfactants do not appreciably interfere. Fig. 2 shows that the inner structure appears to be highly porous, de-FIG. 2. The appearance of the internal structure of polymethylcyanoacrylate nanocapsules by the electron microscopy after spray freezing and cryofracture (see (Bachmann et al 1973) for details).

Laparoscopic CBDE is safe in selected patients. A stratified intraoperative surgical strategy is mandatory in deciding between a transcystic route and choledochotomy with specific indications for each approach. When feasible, laparoscopic choledochotomy is more efficient and safe than the transcystic route, but it is associated with a longer postoperative hospital stay, which is due to external biliary drainage.

Laparoscopic cholecystectomy (LC) is now widely accepted as the modality of choice for the treatment of symptomatic uncomplicated cholelithiasis. The application of the laparoscopic technique in the setting of acute cholecystitis (AC) is more controversial. The precise role as well as the potential benefits of LC in the treatment of the acutely inflamed gallbladder have not been clearly established through large clinical series. The aim of our study was to assess the feasibility, safety, benefits, and specific complications of the laparoscopic approach in patients with AC. A retrospective chart analysis involving the patients admitted to two busy emergency digestive surgical units between October 1990 and December 1997 was carried out. Six hundred and nine patients meeting our criteria for AC were identified and evaluated. Overall complication rate was 15% with 12 postoperative bile leakages (1.97%) and 4 biliary tract injuries (BTI) (0.66%). The overall mortality rate was 0.66%. Local and overall complication rates were significantly correlated with the delay between the onset of acute symptoms and the operation but not the rate of general complications nor deaths. Our results demonstrate the safety and feasibility of LC in the setting of AC. Early cholecystectomy within 4 days is strongly recommended to minimize complications and increase the chances of a successful laparoscopic approach.

Laparoscopy is feasible and safe in cases of peritonitis. Laparoscopic treatment is particularly effective in the case of appendicular and gastroduodenal perforation. In the case of colonic perforation, the conversion rate remains high but with growing experience and surgical skill, more of these cases will be treated laparoscopically in the future.

The diagnostic and therapeutic influence of laparoscopy has been studied in 255 patients presenting with nontraumatic acute abdominal pain. Laparoscopy provided a correct diagnosis in 93% (236 of 255) of the cases, the others requiring a laparotomy. An erroneous preoperative diagnosis was corrected by laparoscopy in 50 patients (20%), which called for a change of treatment in 25 patients (10%). Seventy-three percent (186 of 255) of acute abdominal conditions were treated exclusively by laparoscopy, 23% (58 of 255) by conventional surgery, and 4% (11 of 255) by laparoscopically assisted surgery. Mortality was 2% (5 of 247) and morbidity 11% (28 of 247). We conclude that laparoscopy is a valuable tool for the general surgeon facing a patient with an acute abdomen.