Measurement of the Fluctuations in the Number of Muons in Extensive Air Showers with the Pierre Auger Observatory.

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.

Retroperitoneal abscess after retained stones during laparoscopic cholecystectomy.

Laparoscopic cholecystectomy is associated with a significant risk of gallbladder perforations with bile and stone spillage. The retrieval of dropped stones is sometimes impossible, and intraperitoneally retained stones can be the source of serious complications, such as inflammatory masses or abscesses. The authors describe a patient in whom a large retroperitoneal abscess developed as a result of missed stone fragments during cholecystectomy. Although several cases of intraperitoneal abscess have been reported in the literature, retroperitoneal collection is very uncommon. Crushed and infected stones seem to be the essential prerequisite for abscess formation. Therefore, every attempt should be made to avoid stone spillage and intra-abdominally retained stones. Conversion to open surgery has to be considered in the presence of adverse factors, such as primary acute cholecystitis or cholecystitis induced by previous sphincterotomy, or bilirubinate stones believed to be infected. Abdominal abscess treatment requires removal of missed stones by surgical incision or new laparoscopic procedure because simple percutaneous drainage is usually unsuccessful.

Comparison between the biofragmentable anastomosis ring and stapled anastomoses in the extraperitoneal rectum: a prospective, randomized study.

Serious complications can be carried by intestinal anastomoses, particularly in the distal and proximal part of the gastrointestinal tract. The biofragmentable anastomosis ring (BAR) has been shown to be a safe anastomotic technique, but its clinical applicability in the extraperitoneal rectum has not yet been completely established. This study compared BAR anastomoses and stapled anastomoses in the middle rectum. Thirty-six consecutive patients initially suitable for elective colorectal anastomosis in the middle rectum were enrolled into this study. All patients had intraperitoneal rectum carcinoma, and 31 underwent a colorectal anastomosis in the middle extraperitoneal rectum. They were randomly allocated to a stapled technique or BAR anastomosis. Intraoperative findings and technical drawbacks, tumor behavior, and postoperative course were recorded. All patients were followed up, and late stenosis rate was investigated by endoscopy. The procedure was carried out in each of the 15 patients randomized to receiving a BAR anastomosis. No major difficulties were encountered, and the time needed was even less than that required for a stapled anastomosis. One patient in the stapled group had an early bleeding that required a further laparotomy. No significant differences in postoperative complications were noted between the two groups, although one patient with stapled anastomosis experienced a clinical leakage that needed loop colostomy. Biofragmentability was regular; buttons were eliminated in 3 weeks without any bowel disturbance. BAR ring insertion in the deep pelvis did not produce a shorter colonic resection. The late stenosis rate was similar between the groups. This study shows that in extraperitoneal middle rectum BAR anastomosis is as feasible and safe as the stapled method. The latter is more expensive, and manual suture is more difficult. Therefore the BAR is now the method of choice for this anastomosis in the authors' unit.

[Multidisciplinary treatment of hepatocarcinoma]. / Il trattamento multidisciplinare dell'epatocarcinoma.

Radical treatment of the hepatocellular carcinoma (HCC) is complete surgical removal; it may be done by resection or total hepatectomy. Although multicentric carcinogenesis predicts that liver transplantation is likely adequate to treat both the hepatoma and the underlying cirrhosis, it doesn't seem justified in the advanced stages or in absence of end-stage liver disease and therefore liver resection remains the treatment of choice for radical cure of HCC. However, low resectability and high recurrence rate make surgery alone ineffective. Unresectable HCC may be converted to resectable by multimodality radiation/chemotherapy, and embolization of portal branch feeding tumour, improving the function of the nonembolized liver, can extend the surgical indications for HCC. Adjuvant chemoembolization has already shown to reduce recurrence rate after radical resection and it should be widely applied. In unresectable or not converted HCCs as well as in postoperative recurrence, alternative therapies, particularly as multimodality treatment, can improve survival rate. To date, multidisciplinary treatment of hepatocellular carcinoma, waiting for further studies on newer modalities (prevention and gene therapy, especially), represents the best way to improve long-term results.