Color Doppler Ultrasound Detection and Classification of the Tangential Hepatic Vein before Laparoscopic Cholecystectomy

Background: Unexpected fatal bleeding from the gallbladder bed during laparoscopic cholecystectomy is often associated with injury to the middle hepatic vein. This paper studies whether preoperative color Doppler ultrasound is effective in reducing the risk of injury. Also a venous classification is suggested. Methods: Between June 1999 and February 2004, 2,146 patients undergoing laparoscopic cholecystectomy by standard method received preoperative color Doppler ultrasound examinations. The closest distance between the hepatic vein and the gallbladder was studied. Also, cases of liver cirrhosis, number of conversions to open cholecystectomy, intraoperative blood loss, operative time, complications, and hospital stay were recorded (group D). At the end of the study, we retrospectively reviewed the same parameter of another 2,146 patients who received laparoscopic cholecystectomy without preoperative color Doppler ultrasound between the period of March 1995 and June 1999 (group ND). Results: In group D, 108 patients had cirrhosis. Four hundred and ninety-six patients (27 cases of cirrhosis) had a closest distance of 1 mm or less between the vein and the gallbladder. There were two conversions to open cholecystectomy, but none related to gallbladder bed bleeding. In group ND, there were five conversions, including four cases of gallbladder bed bleeding from the middle hepatic vein and one case of severe adhesion. The conversion rate was significantly higher. In group ND, the mean intraoperative blood loss in the cases of liver cirrhosis was significantly greater. Also, the operative time of patients with the closest vein and gallbladder distance of 1 mm or less in group D was significantly longer. Conclusions: Color Doppler ultrasound is an effective method for detecting the presence of potential bleeders. Although the operative time will be a bit longer, the operation can be done under meticulous care and complete preparation, so that the conversion rate and the risk of fatal hemorrhage can be reduced, especially in patients with liver cirrhosis.     

On the Fundamental Group of Manifolds of Non-positive Curvature

We prove theorems on the structure of the fundamental group of a compact riemannian manifold of non-positive curvature. In particular, a conjecture of J. Wolf [J. Differential Geometry, 2, 421-446 (1968)] is proved.     

Relapsing polychondritis studied by computed tomography

Computed tomographic findings in a patient with relapsing polychondritis are described. Collapse of the cartilage of the nose and calcification in cartilages of the ears were clearly demonstrated. CT scanning was also helpful in evaluating the tracheobronchial tree for airway compromise, which could prove fatal in this condition.     

On the structure of complete simply-connected Kähler manifolds with nonpositive curvature

We prove that a complete simply-connected Kähler manifold with nonpositive sectional curvature is biholomorphic to the complex Euclidean space if the curvature is suitably small at infinity.     

Laparoscopic virtual reality training: are 30 repetitions enough?

BACKGROUND: Current literature suggests that novices reach a plateau after two to seven trials when training on the MIST VR laparoscopic virtual reality system. We hypothesize that significant benefit may be gained through additional training. MATERIALS AND METHODS: Second-year medical students (n = 12) voluntarily enrolled under an IRB-approved protocol for MIST VR training. All subjects completed pre- and posttraining questionnaires and performed 30 repetitions of 12 tasks. Performance data were automatically recorded for each trial. Learning curves for each task were generated by fitting spline curves to the mean overall scores for each repetition. Scores were assessed for plateaus by repeated measures, slope, and best score. RESULTS: On average, subjects completed training in 7.1 h. (range, 5.9-9.2). Two to seven performance plateaus were identified for each of the 12 MIST VR tasks. Initial plateaus were found for all tasks by the 8th repetition; however, ultimate plateaus were not reached until 21-29 repetitions. Overall best score was reached between 20 and 30 repetitions and occurred beyond the ultimate plateau for 9 tasks. CONCLUSIONS: These data indicate that a lengthy learning curve exists for novices and may be seen throughout 30 repetitions and possibly beyond. Performance plateaus may not reliably determine training endpoints. We conclude that a significant and variable amount of training may be required to achieve maximal benefit. Neither a predetermined training duration nor an arbitrary number of repetitions may be adequate to ensure laparoscopic proficiency following simulator training. Standards which define performance-based endpoints should be established.     

Thomas Hodgkin's journey through Spain in 1863 and 1864

In 1863 and 1864, Thomas Hodgkin travelled to Morocco, accompanying his close friend Sir Moses Montefiore, who stopped in Madrid on the way there and back to attend an audience with the Queen of Spain. Thomas Hodgkin's impressions of Spain were recounted in his book Narrative of a Journey to Morocco. The book reveals new aspects of Hodgkin's personality as well as his capacity for observation. It also describes Spain in the second half of the nineteenth century. Thus Thomas Hodgkin was a witness to one of the most vivid periods of the history of the country. The paper considers both aspects of Hodgkin's commentaries on Spain.