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Biomedical subjects

J Machi

Publications and source records attributed to J Machi.

At least 55 records · Page 3Linked to original sources
PubMed1991

Detection of preoperatively unrecognized multiple pancreatic pseudocysts by intraoperative ultrasonography. Report of two cases.

During two pancreatic operations, intraoperative ultrasonography detected multiple pancreatic pseudocysts that were unrecognized preoperatively. In each operation, a single pseudocyst was detected by preoperative ultrasonography, computed tomography, and intraoperative surgical exploration. In addition, high-resolution ultrasonography used during the operations also identified and precisely localized additional smaller pseudocysts. Also, the use of color Doppler imaging during the operations enabled the delineation of small blood vessels around the pseudocysts. The accurate diagnosis of multiple pseudocysts and the precise anatomic information provided by intraoperative ultrasonography permitted appropriate surgical treatment of the pancreatic pseudocysts which, in turn, might help prevent recurrence of the disease.

Adult↗
PubMed1990

Transdiaphragmatic liver scanning: a new intraoperative imaging technique for examination of the liver from the thoracic cavity.

In order to examine the liver during thoracotomy, a new intraoperative imaging technique called "transdiaphragmatic liver scanning" was developed. Transdiaphragmatic scanning performed with high-frequency transducers provided clear visualization of the entire liver from the thoracic cavity through the diaphragm. In our study, transdiaphragmatic scanning was used in 27 thoracotomy operations performed for the treatment of malignant diseases, including lung and esophageal cancers. One 5-mm liver cyst, one 3-mm x 4-mm hemangioma, and one 5-mm x 6-mm ill-defined lesion (possible metastasis), all of which were unrecognized preoperatively, were detected. In 3 operations, preoperatively suspected liver metastases were excluded by transdiaphragmatic scanning. Because transdiaphragmatic scanning provides high-resolution images of the liver and is the only method capable of examining the liver during thoracotomy, this intraoperative scanning technique may become a useful tool in the evaluation of liver metastases from thoracic or mediastinal malignancies.

Cysts↗
PubMed1990

Operative ultrasound guidance for various surgical procedures.

Although percutaneous ultrasound-guided technique is currently a common practice, the use of ultrasound for the purpose of guidance during surgery has not been widely practiced. Over a period of 10 years, we performed operative ultrasonography in 2,314 operations. In 321 of these operations, operative ultrasound guidance was performed for direct assistance of various surgical procedures, particularly during operations on the brain and spinal cord, liver, pancreas, and kidney. Procedures guided by operative ultrasound were classified into the following categories: intraoperative needle placement for fluid aspiration (n = 38), agent injection (n = 14), catheter introduction (n = 27), biopsy (n = 57), surgical tissue dissection for incision (n = 48), resection (n = 82) of organs, and extraction (n = 55) of stones or foreign bodies. Operative ultrasound guidance facilitates various surgical procedures and is considered a useful modality for reducing operative complications, shortening operating time, performing otherwise impossible procedures, and, at times, developing new surgical operations.

Humans↗
PubMed1990

Ultrasonic tissue characterization of blood clots.

Ultrasonic tissue characterization based on an analysis of the power spectrum of backscattered signals obtained with ultrasound was used to distinguish morphologic components of blood clots. The three morphologic features for which discrimination was attempted were loose fibrin, red-cell, and dense fibrin clots. The UTC was able to distinguish the morphologic blood components tested. This in vitro work was based on the analysis of parameters related to ultrasound-tissue interaction and on inferences related to the physical properties of scatterer properties (scatterer size, scatterer concentration, and ratio of scatterer to medium acoustic impedances). The ability to distinguish these blood-clot components suggests that UTC may be able to distinguish red from white thrombi and to assess the structures and changes within thrombi associated with the age of the thrombus, their mechanical properties, and treatment monitoring.

Blood Coagulation↗
PubMed1989

Efficacy of measuring BUN in assessing children with dehydration due to gastroenteritis.

We conducted a prospective study of 50 consecutive cases of children with gastroenteritis and dehydration to assess the correlation of alterations in the blood urea nitrogen (BUN) concentration. Symptoms included 24 children with vomiting and 26 with vomiting and diarrhea. All children were estimably dehydrated-appearing on examination by traditionally used criteria and had metabolic acidosis (serum bicarbonate concentration of less than 20 mEq/L) and increased anion gap (more than 12 mEq/L). Of these 50 children, 44 (88%) had a BUN concentration within the limits of normal--17 were less than or equal to 10 mg/dL, 17 were between 11 and 14 mg/dL, and ten were between 14 and 18 mg/dL. We discuss the physiologic factors that influence the BUN concentration in conditions of dehydration. Although commonly used, measurement of the magnitude of the BUN concentration is not an accurate method for assessing the hydration status of children with dehydration due to gastroenteritis.

Bicarbonates↗
PubMed1989

The fate of unrepaired minor technical defects detected by intraoperative ultrasonography during carotid endarterectomy.

This report describes the natural history of unrepaired minor technical defects detected by intraoperative B-mode ultrasonography during carotid endarterectomy. Intraoperative ultrasonography was used to assess the technical adequacy of 80 carotid endarterectomies. Sixty-two arteries were normal on intraoperative ultrasound examination, whereas the remaining 18 arteries had a total of 21 minor residual technical defects. The 21 minor defects consisted of four internal carotid artery lesions, nine common carotid artery lesions, and eight external carotid artery lesions, 19 had 1 to 3 mm intimal flaps, and two had small stenoses. Sixteen of the 19 intimal flaps resolved before the first postoperative ultrasound study. These arteries had normal examination results, which indicated that these intimal flaps had healed. The two stenoses detected intraoperatively could not be detected by postoperative carotid duplex scanning at 1 month follow-up. No statistically significant relationship was found between the presence of a minor residual defect on intraoperative ultrasonography and the subsequent development of recurrent stenosis or occlusion in any of the arteries assessed. These data suggest that certain minor technical defects in the carotid artery that were detected by intraoperative ultrasonography are benign and may not require repeat exploration of the carotid artery for repair.

Actuarial Analysis↗
PubMed1989

Overview of benefits of operative ultrasonography during a ten year period.

From 1979 to 1988, we have performed operative ultrasonography in 2,299 operations in various surgical fields. By analyzing the results of operative ultrasonography, we defined and summarized its benefits into four categories: acquisition of new information not otherwise available; complement to or replacement for operative radiography; guidance of surgical manipulation; and confirmation of completion of operation. Based on one or more of these benefits occurring, operative ultrasonography was judged to be useful in 2,103 of 2,299 operations (91.5%). The overall impact of operative ultrasonography has been to reduce surgical tissue dissection, reduce operating time, decrease the need for operative radiography, and enable surgeons to devise new surgical procedures. Because of its benefits, the wider use of operative ultrasonography is encouraged.

Humans↗
PubMed1989

Operative ultrasonography for lung cancer surgery.

During 60 operations for lung cancer, high-resolution (7.5 MHz) operative ultrasonography was performed to evaluate direct cardiovascular invasion of tumor (24 operations), lymph node metastasis (30 operations), liver metastasis (13 operations). Immediately after thoracotomy or sternotomy but before tissue dissection, operative scanning enabled delineation and evaluation of the evaluation of the vessels and heart (atrium) behind or within the tumor and detection of regional lymph nodes. The accuracy of operative ultrasound in diagnosing the presence or the extent of cardiovascular invasion was 91.7% (22 of 24 operations), which was significantly (p less than 0.02) higher than preoperative studies (62.5%), including computed tomography and angiography. Of the 24 surgical procedures, 23 were consistent with operations proposed on the basis of operative ultrasound findings, whereas only 16 were consistent with preoperatively proposed (p less than 0.01). Operative ultrasound provided the capability of depicting lymph nodes as small as 3 mm. More lymph nodes (8.0 +/- 1.84 nodes per cancer) were detected with operative ultrasound than with computed tomography (4.8 +/- 1.56 nodes) (p less than 0.001); however, the sensitivity and specificity of operative ultrasound in determining lymph node metastasis were 82.4% and 67.3%, respectively. No liver metastasis was identified. The information provided by operative ultrasound regarding cardiovascular invasion and lymph node and liver metastasis was considered helpful in selecting the type of surgical procedure an in avoiding unnecessary tissue dissection.

Adult↗
PubMed1988

Mediastinal lymphnode dissection procedure during esophageal cancer operation--carefully considered for preserving respiratory function.

In 22 patients with esophageal cancer, mediastinal lymphnode dissection procedure, with preservation of the right bronchial artery and pulmonary branches of the right vagus nerve, was performed during radical esophagectomy. In patients who underwent this procedure, respiratory function was sufficiently maintained against severe complications and the operative and hospital death rate was less than that of other esophagectomized patients.

Bronchial Arteries↗
PubMed1988

A latissimus dorsi muscle flap used for repair of the esophagus after enucleation of a giant leiomyoma--a case report.

A giant leiomyoma of the esophagus, 11.5 X 5.0 cm in size, which occupied half of the esophageal circumference, was surgically enucleated. A small epithelial defect caused by the enucleation of the tumor was directly closed, and a large muscular defect was covered with a latissimus dorsi muscle flap, introduced into the thoracic cavity through the space where the second rib had been resected. Postoperatively, a leakage at the epithelial suture line was noted, however, it was localized by the muscle flap coverage and spontaneously healed two weeks postoperatively. During the follow-up period of 1.5 years, no diverticle formation or stenosis occurred, and the patient had no complaints. The present clinical experience indicates that this procedure may be a useful method of grafting after excision of giant leiomyoma of the esophagus.

Adult↗
PubMed1988

Evaluation of endorectal ultrasound for the assessment of wall invasion of rectal cancer. Report of a case.

To accurately assess the depth of cancer invasion, endorectal ultrasound was performed using a radial scanner (Aloka, 7.5 MHz) in 145 patients with rectal cancer. High-resolution ultrasound clearly depicted five- or seven-layer echographic structures in the normal rectal wall, and demonstrated cancer as a hypoechoic lesion. These layer structures provided an important feature in determining the depth of cancer invasion. Rectal cancers of 122 patients were examined thoroughly by endorectal ultrasound. In 95 of these patients (77.9 percent), ultrasonic assessment of the depth of cancer invasion as classified in four groups was correct, corresponding accurately to the microscopic findings. Ultrasonography overestimated the depth of cancer invasion in 21 patients, however, and underestimated it in six patients. This study indicated that a cause of the overestimation was inflammatory cell infiltration around cancer, and that one possible cause of underestimation was microscopically minimal invasion of cancer. Although there are certain limitations of endorectal ultrasound, this ultrasound technique will provide valuable information to determine the preoperative staging of rectal cancer.

Female↗