Endohyperthermia--experimental evaluation of a new therapeutic approach for treatment of biliary carcinoma.

BACKGROUND AND STUDY AIMS: To improve the prognosis of patients with unresectable, locally advanced bile duct carcinoma, new treatment strategies need to be evaluated. Hyperthermia has been successfully applied as part of multimodal therapy in esophageal and rectal carcinoma. We performed in-vitro and in-vivo experiments with a new intraluminal hyperthermia system in the biliary tract. METHODS: A radiofrequency system (13.56 MHz, Endoradiotherm XERT-200A; Olympus Optical Co., Tokyo, Japan) was used with a special intraluminal microelectrode (diameter 4.5 mm, length 40 mm) covered by a silicone balloon with cooling water and a large counter electrode for focusing the electromagnetic field around the electrode. The heating capacity of the endohyperthermia unit was examined in vitro in a muscle-equivalent phantom (agar 4 %), in isolated livers of pigs and cows, as well as in vivo in anesthetized sheep. Continuous thermometry was done with thermosensors at the applicator surface, and with multichannel thermocouple probes in the environment of the applicator. RESULTS: Endohyperthermia induced a homogeneous heating of the phantom and the isolated liver bile duct preparation to a temperature > or = 40 degrees C in an area at least 10 mm in depth. After placement of the applicator into the common bile duct of anesthetized sheep, endohyperthermia led to a consistent and repeatable heating of the surrounding tissue to 40.5 +/- 0.5 degrees C at 1 cm distance, and 39.9 +/- 0.7 degrees C at 2 cm distance. Blood pressure, heart rate, and systemic temperature did not change in vivo. Histological examination of the bile duct showed superficial mucosal necrosis (depth 100-200 microm), microvascular damage with petechiae, congestion and edema of the bile duct wall and adventitia after hyperthermia treatment in vivo. CONCLUSIONS: The intraluminal endohyperthermia system produces consistent and repeatable heating of the surrounding tissue. Since effective thermal power can reach a depth of up to 2 cm, tumors may also be heated adequately.

[Antibiotic prophylaxis using cefuroxime in bile duct endoscopy]. / Antibiotische Prophylaxe mit Cefuroxim bei endoskopischen Eingriffen an den Gallenwegen.

OBJECTIVE: To assess prospectively the effectiveness of a single prophylactic dose of cefuroxim before therapeutic endoscopy, in view of the general practice not to give antibiotics routinely. PATIENTS AND METHODS: In a prospective study endoscopic retrograde cholangiopancreatography (ERCP) or percutaneous transhepatic cholangiography with drainage (PTCD) together with simultaneous stone extraction, dilatation or stent implantation were performed in 99 patients (51 men, 48 women; mean age 60.6 +/- 19.2 years). Group A (n = 49) received 1500 mg cefuroxim i.e. 30 min before the procedure, while none was given to group A patients (n = 50). Several blood cultures were taken up to 60 min after the endoscopy. The number of septicaemias (bacteraemia with fever, rigor, circulatory reactions, leukocytosis or leukopenia) were noted. Bile cultures were obtained in 56 patients with indwelling biliary drainage. RESULTS: Incidence of bacteraemia was 6.1% (3 of 49) in group A, 16% (8 of 50) in group B, but this difference is not statistically significant. The septicaemia rate was 6.1% in group A and 10% in group B (not significant). There were eleven positive blood cultures with 12 different microorganisms, Escherichia coli in four (A: n = 3). In vitro cefuroxim sensitivity was 53.3%. 25 different bacterial species were isolated from 73.2% of bile cultures, of which 53.4% were sensitive to cefuroxim and 8.2% moderately so. CONCLUSION: Although the obtained differences between the two groups were not statistically different, the reduction in bacteraemia/septicaemia rate may be of clinical use. Further studies are needed with higher dosages or antibiotic combinations to improve these results.