Slip pulse and resonance of the Kathmandu basin during the 2015 Gorkha earthquake, Nepal.

Detailed geodetic imaging of earthquake ruptures enhances our understanding of earthquake physics and associated ground shaking. The 25 April 2015 moment magnitude 7.8 earthquake in Gorkha, Nepal was the first large continental megathrust rupture to have occurred beneath a high-rate (5-hertz) Global Positioning System (GPS) network. We used GPS and interferometric synthetic aperture radar data to model the earthquake rupture as a slip pulse ~20 kilometers in width, ~6 seconds in duration, and with a peak sliding velocity of 1.1 meters per second, which propagated toward the Kathmandu basin at ~3.3 kilometers per second over ~140 kilometers. The smooth slip onset, indicating a large (~5-meter) slip-weakening distance, caused moderate ground shaking at high frequencies (>1 hertz; peak ground acceleration, ~16% of Earth's gravity) and minimized damage to vernacular dwellings. Whole-basin resonance at a period of 4 to 5 seconds caused the collapse of tall structures, including cultural artifacts.

Short gastric vessels division in Laparoscopic Nissen Fundoplication.

BACKGROUND/AIMS: To divide or not the short gastric vessels during Laparoscopic Fundoplication (LF) is still controversial. This retrospective study is based on short gastric vessels division (SGVsD), if necessary, during LF to construct a satisfactory loose wrap and to evaluate its effect upon the symptomatic and physiologic outcome in patients with proven GERD. METHODOLOGY: 150 patients (90 males, 60 females) with a mean age of 37 +/- 9 with typical symptoms of GERD, adequate motility study and positive 24-hour pH studies underwent LF; 100 (66.7%) were feasible after careful and complete fundal dissection without SGVsD while, 50 (33.3%) were not possible except with SGVsD. Outcome measures included assessment of the relief of the primary symptom responsible for surgery; repeated upper endoscopy and barium study. Postoperative 24-hour esophageal pH and LES manometry were performed in 110 patients. RESULTS: The mean operative time was prolonged with short gastric division (130 +/- 60 vs. 90 +/- 40 minutes). At a mean period of follow-up of 35 +/- 12 months, relief of the primary symptom responsible for surgery was achieved in 92.2% of patients with division and 87.5% of patients without. Recurrent attacks of abdominal distension were documented in 2 patients (5.6%) with division and 12 patients (16%) without division. Occasional dysphagia not present before surgery occurred in 27 patients at 3 months; 11 (31.4%) with division and 16 (21.3%) without, and decreased to 11 patients by 12 months after surgery; 2 (5.7%) with division and 9 (12%) without; only one case of those without division required 5 sets of endoscopic dilatation. Endoscopic esophagitis healed in all patients with division and 71 of 75 patients (94.7%) without. LES pressures had returned to normal in all patients except one case without division (1.3%) with a higher mean pressure among those without division (22.3 mmHg vs. 18.5 mmHg) and a better relaxation with division (89.9% vs. 80.5%). 24-hour esophageal acid exposure had returned to normal in 33 of 35 patients (94.3%) with division and 66 of 75 patients (88%) without. CONCLUSIONS: Construction of a satisfactory loose Nissen Fundoplication was feasible in two thirds of patients without SGVsD. Despite prolongation of the operative time, SGVsD provides a better symptomatic and physiologic outcome.

Outcome after resection of central cholangiocarcinoma: preliminary experience with 46 patients in a single center.

BACKGROUND/AIMS: Despite the enormous progress in surgery the management of cholangiocarcinoma remains a problem. In this study we present our preliminary experience in the surgical treatment of central cholangiocarcinoma. METHODOLOGY: Between May 1997 and December 2001, 175 patients with central cholangiocarcinoma were admitted to our center. Of the 175 patients, 54 cases subjected to surgery, the remaining 131 patients did not undergo surgery because of advanced disease, advanced liver cirrhosis and poor general condition. Forty-six patients underwent surgical excision, their mean age was 53 +/- 3 years, and male to female ratio was 74-26%. All patients presented with jaundice associated with pain (30%) or biliary stones (32%). Surgical resection of the bile duct with or without part of segment IV were done in fourteen patients and bile duct resection together with major hepatectomy had been done in the remaining 28 patients. RESULTS: Hospital mortality occurred in 10.8%; the main cause of mortality was hepatic cell failure. The most common complications were hepatic cell failure that occurred in 7 cases (15%), biliary leakage in 8 cases (17%), gastrointestinal bleeding in 3 cases (6.5%) and wound infection in 3 cases (6.5%). Late complication in the form of recurrence occurred in 12 cases (29.5%). cholangitis in 8 cases (19.5%), hepatic cell failure in 5 (12%) and gastrointestinal bleeding in 2 (4.8%). At the end of the study, 19 patients (46%) were alive with mean follow-up of 16.6 +/- 9 months. The survival rate at 6, 12, 18, 24 months was 92, 82, 52, 25, 18%, respectively. Recurrence and cholangitis were found significantly higher in the group without hepatectomy than the group after hepatectomy (p < 0.0001, p < 0.0016, respectively). CONCLUSIONS: From our results we can conclude that major hepatectomy with excision of the extrahepatic bile duct system and caudate lobe resection may be recommended for the surgical treatment of central cholangiocarcinoma in selected cases.

Determination of sevoflurane alveolar concentration for tracheal intubation with remifentanil, and no muscle relaxant.

The sevoflurane alveolar concentration needed for tracheal intubation with remifentanil was studied in 26 adult patients premedicated with 100 mg hydroxyzine. Anaesthesia was induced with sevoflurane in oxygen. The concentration was determined by Dixon's up-and-down method. The first patient was tested at 4.5%. One minute after obtaining the preselected value, remifentanil 1 microg.kg-1 was injected for 60 s followed by an infusion of 0.25 microg.kg-1. min-1. Ventilation was then manually assisted for 2 min and tracheal intubation was attempted. Tracheal intubation conditions and responses to intubation were noted. Heart rate and mean arterial pressure were recorded before induction, before remifentanil injection, and before and 3 min after tracheal intubation. The concentration for acceptable intubating conditions was 2.5 +/- 0.7%. From logistic regression, ED50 and ED95 were 2.0% (95% CI 1.3-2.5) and 3.2% (95% CI 2.6-5.6), respectively. With sevoflurane 2.5%, heart rate and mean arterial pressure decreased by 18% and 15%, respectively, after remifentanil administration and increased slightly after tracheal intubation.