Changes of Electroencephalographic Bicoherence during Isoflurane Anesthesia Combined with Epidural Anesthesia

Background: The authors previously reported that, during isoflurane anesthesia, electroencephalographic bicoherence values changed in a fairly restricted region of frequency versus frequency space. The aim of the current study was to clarify the relation between electroencephalographic bicoherence and the isoflurane concentration.

Methods: Thirty elective abdominal surgery patients (male and female, aged 34-77 yr, American Society of Anesthesiologists physical status I-II) were enrolled. After electroencephalogram recording with patients in an awake state, anesthesia was induced with 3 mg/kg thiopental and maintained with oxygen and isoflurane. Continuous epidural anesthesia with 80-100 mg/kg 1% lidocaine was also administered. Using software they developed, the authors continuously recorded the FP1-A1 lead of the electroencephalographic signal and expired isoflurane concentration to an IBM-PC compatible computer. After confirming the steady state of each isoflurane (end-tidal concentration at 0.3, 0.5, 0.7, 0.9, 1.1, 1.3, and 1.5%), electroencephalographic bicoherence values were calculated.

Results: In a light anesthetic state, electroencephalographic bicoherence values were low (generally <= 15.0%). At increased concentrations of isoflurane, two peaks of electroencephalographic bicoherence emerged along the diagonal line (f1 = f2). The peak emerged at around 4.0 Hz and grew higher as isoflurane concentration increased until it reached a plateau (43.8 +/- 3.5%, mean +/- SD) at isoflurane 0.9%. The other peak, at about 10.0 Hz, also became significantly higher and reached a plateau (32.6 +/- 9.2%) at isoflurane 0.9%; at isoflurane 1.3%, however, this peak slightly decreased.     

ENDOSCOPIC OBSERVATION OF MUCOSAL SPREAD LESION OF CHOLANGIOCARCINOMA USING PERORAL CHOLANGIOSCOPY WITH NARROW BAND IMAGING

A 69‐year‐old man was admitted to Toho University Omori Medical Center complaining of icterus. Abdominal computed tomography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography were suspicious of cholangioma of inferior bile duct. Peroral cholangioscopy using narrow band imaging (NBI) was performed and it was possible to diagnose the mucosal spread lesions of cholangioma. Histological findings reflected the endoscopic findings. Mucosal spread lesions of cholangiocarcinoma were successfully diagnosed using the CHF‐B260 for NBI.     

A surgical case of ventricular septal perforation after repairing left ventricular free wall rupture.

A 78-year-old woman with diagnosis of acute myocardial infarction (AMI) in the anteroseptal area fell into cardiogenic shock suddenly just before starting percutaneous coronary intervention (PCI). Echocardiography showed left ventricular free wall rupture, then an emergent operation was performed by sutureless patch repair using collagen fleece with fibrinogen-based impregnation. Eight days later from the initial operation, the onset of ventricular septal perforation (VSP) was recognized. Fifteen days after, the infarct exclusion technique with endocardial patch was performed. She has been doing well 4 months after the operation without residual shunt. To our best knowledge, this is the first surgical case report that free wall rupture of left ventricle and VSP which are serious complications after myocardial infarction happened in succession.     

Triangle target principle for the placement of trocars during video-assisted thoracic surgery.

OBJECTIVE: The baseball-diamond principle is generally used for trocar placement during video-assisted thoracic surgery; however, we are unable to treat all peripheral lung lesions using this principle. Therefore, we have developed another method for determining trocar placement based on a modification of the conventional principle. We have termed this method the triangle target principle. This report describes the instrument positioning that we now use for many video-assisted thoracic surgical procedures. METHODS: We position 3 trocars in an equilateral triangle, with the target lesion at the apex. One vertex of the base becomes the site of the first trocar placement for introduction of the thoracoscopic camera. Another vertex of the base becomes the site for the second trocar for forceps or the endoscopic stapler. The third trocar is for forceps and is inserted to create the vicinity of target lesion. Four types of the triangle target principle were developed according to sites of the target lesion. RESULTS: Between January 2000 and December 2002, we used this principle for 161 patients who underwent video-assisted thoracic surgery and all intrathoracic lesions were accessible except in 3 patients requiring intraoperative modifications. CONCLUSIONS: We conclude that video-assisted thoracic surgery by this principle is more effective and easier than the conventional principle to treat intrathoracic disease.     

Surgical management of endocrine tumor of the pancreas in Japan

Endocrine tumor of the pancreas is potentially malignant. A multicenter analysis of these tumors was conducted to clarity the present status of their surgical management and the subsequent long-term surgical results. The Japan pancreatoduodenectomy (JPD) study group carried out the study; 368 patients were enrolled and variables related to tumor characteristics, surgery, and survival were retrospectively analyzed. There were 222 patients with functioning tumor and 143 patients with nonfunctioning tumor. Malignant tumor was found in 140 of 368 (38%) of the patients, and 63/140 (45%) of these patients had metastatic lesion; the most common site of the metastasis was liver 34/136 (25%), followed by regional lymph nodes 26/136 (19%). Pancreatic resection was performed in 91% of patients with nonfunctional tumor and in 83% of those with malignant tumor, and 73% of the pancreatic resections were done with lymph node dissection. The overall 5-year actuarial survival rate was 76% in patients with malignant tumor. The actuarial 5-year survival rate was 93% in the patients without metastasis and 83% in patients who received curative resection. Multivariate analysis showed that the presence or absence of synchronous metastasis was the sole significant prognostic factor. The results suggest that: (i) malignant endocrine tumor of the pancreas is a curable malignancy when pancreatic resection with lymph node dissection is adopted and (ii) that synchronous metastasis is the dominant prognostic factor. This study was carried out as a group project. The authors' institutions are as follows     

An elderly case of idiopathic retroperitoneal fibrosis]

An elderly case of idiopathic retroperitoneal fibrosis (IRPF) with bilateral ureteral obstruction was reported. A 74-year-old man was admitted with complaints of general fatigue and loss of appetite. An elastic hard mass with a smooth surface was palpated in the left upper quadrant of the abdomen. Abnormal ESR and CRP were noticed. Abdominal ultrasonography showed both a homoechoic mass which surrounded the aorta in the retroperitoneal space and bilateral hydronephrosis. Computed tomography revealed a retroperitoneal mass involving bilateral ureters. Magnetic resonance imaging demonstrated a mass with a sharp image and signal intensity. Furthermore the morphological relationship between the mass and the ureters and major vessels clearly indicated the characteristics of benign retroperitoneal fibrosis. Based upon the above findings, a diagnosis of IRPF was made. After confirming the histological diagnosis by biopsy, treatment consisting of bilateral ureterolysis, intra-abdominal transposition of ureters and oral administration of prednisolone was performed, resulting in a normalization of laboratory findings. Analysis of 86 previously cases of IRPF reported up to 1990 in Japan, revealed the peak age to be in the 7th decade with predominance in males (males: females = 57:29).