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Biomedical subjects

J Machi

Publications and source records attributed to J Machi.

At least 73 records · Page 4Linked to original sources
PubMed1987

Intrathoracic application of the latissimus dorsi muscle for esophageal cancer operation.

In order to reinforce the difficult closure of the bronchial stump, or esophageal anastomosis, a pedicle flap, taken from the latissimus dorsi muscle, was applied to 7 patients with tracheal repairs, and 11 patients with extensively dissected areas, at the time of esophageal cancer surgery. Utilizing this technique, the complications associated with extended esophagectomy could be minimized. Intrathoracic application of the latissimus dorsi muscle flap is a useful method of supporting extended esophagectomy for esophageal cancer.

Esophageal Neoplasms↗
PubMed1987

Safe jugular and subclavian venipuncture under ultrasonographic guidance.

Although jugular and subclavian venipuncture is a valuable technique and frequently utilized, blind venipuncture is at times associated with complications such as arterial puncture, pneumothorax, and malpositioning of catheters. We performed venipuncture under the guidance of high-resolution real-time ultrasonography, and these catheter-related complications were prevented. Jugular, subclavian and innominate veins and arteries, the pleura, and the lung are all delineated by supraclavicular and subclavicular scanning, and the needle and catheter can also be visualized. Ultrasonographically-assisted jugular and subclavian venipuncture is a simple and helpful procedure to carry out safe venipuncture. This method is particularly recommended for less experienced physicians and for more accurate puncture in patients with distorted cervical or subclavicular anatomic characteristics.

Humans↗
PubMed1987

Protamine-induced platelet aggregation and clotting investigated by ultrasound.

Using high-resolution real-time ultrasound to monitor platelet aggregation and plasma clotting, the effect of protamine on platelets was evaluated in a dynamic system of plasma in vitro. Protamine induced platelet aggregation preceding plasma clotting at both low (1.6 s-1) and moderate (22.6 s-1) shear rates. The onset of aggregation and clotting was accelerated at the higher shear rate. Low-shear clots were heterogeneous on ultrasonic imaging, whereas moderate-shear clots were more densely homogeneous. Protamine-induced platelet aggregation was reversed by additional heparin. Pretreatment of plasma with prostacyclin prevented protamine-induced aggregation, but clot formation occurred. However, such clots were less echogenic. EGTA and hirudin inhibited both aggregation and clotting. Our ultrasonic aggregometry showed that platelet aggregation was induced by protamine before clots formed, and that not only shear rate but platelet activation might affect the rate and composition of plasma clots.

Adult↗
PubMed1987

Intraoperative ultrasonography in screening for liver metastases from colorectal cancer: comparative accuracy with traditional procedures.

As a new screening procedure, intraoperative ultrasonography using high-resolution real-time instruments was used routinely in 84 colorectal cancer operations to scan the entire liver for liver metastases. In 10 operations (11.9%), intraoperative ultrasonography identified 14 previously unrecognized metastatic tumors, all of which were less than 2 cm in size and were nonpalpable. The sensitivity of this technique in detecting metastatic liver lesions (97.8%) was significantly superior (p less than 0.01) to that of preoperative ultrasound (41.3%), computed tomography (47.8%), and surgical exploration (58.7%), while the specificity of each test was comparable (approximately 90%). High-resolution intraoperative ultrasonography is safe, simple to perform and more accurate than preoperative imaging and surgical exploratory methods. Therefore its use is encouraged during colorectal cancer surgery for screening of liver metastases.

Adult↗
PubMed1987

A new technique for esophageal reconstruction by combined skin and muscle flaps after failure in primary colonic interposition.

A new procedure is presented for esophageal reconstruction using the skin flap combined with the overlying muscle flap in a situation in which preceding cervical esophagostomy and antesternal colostomy have been performed. A conventional musculocutaneous flap may be used for the second stage of the operation. However, our method has several advantages. The skin canal, which is the most important part of this reconstruction, is created using the skin of the anterior chest wall without transferring cutaneous tissue from other places. Therefore, the operative procedure becomes simpler and the blood supply to the skin canal is more assured. While blood of the wall of the canal is supposed to be supplied initially from internal mammary and intercostal arteries, the muscle flap over the canal may subsequently provide more blood to the skin canal. In addition to sufficient blood supply, the length of a suture line for creating the skin canal is minimal, and, thereby, the possibility of postoperative leakage can be diminished. Because both esophagostoma and colostoma are not damaged in the second stage of the operation, strictures at these sites are not likely to occur. Furthermore, the muscle flap serves as a physical protector for the canal, and presents a suitable bed for the split thickness graft. Our two stage operation using combined skin and muscle flaps after antesternal colostomy is a safe, simple and assured technique for the compromised colonic segment at primary esophageal reconstruction. This procedure is also applicable to the patient in whom use of a stomach tube for esophageal replacement is attempted but primary cervical esophagogastrotomy is not possible.

Colon↗
PubMed1986

Detection of unrecognized liver metastases from colorectal cancers by routine use of operative ultrasonography.

The importance of diagnosis and detection of liver metastases cannot be overemphasized for the treatment and prognosis of colorectal cancers. As a new diagnostic technique, operative ultrasonography has been performed during 33 operations for colorectal cancers including three operations for metachronous liver metastases. Of these, in five patients (15.2 percent) ultrasonography using 5- or 7.5-MHz instruments identified metastatic tumors that had not been diagnosed during preoperative imaging studies or at exploration. Most of these tumors were approximately 1 cm in size and nonpalpable. Cases of these five patients are presented in this report. High-resolution operative ultrasonography is considered to be a valuable method for detection of unrecognized metastatic tumors and for precise localization and spatial assessment of these hepatic lesions. Because it is safe, simple, and highly sensitive, the routine use of operative ultrasound is encouraged during surgery upon colorectal cancers for systematic screening of metastatic liver tumors.

Adult↗
PubMed1986

Normal stomach wall and gastric cancer: evaluation with high-resolution operative US.

Operative ultrasound examinations were performed using a 7.5-MHz transducer during nine operations for advanced gastric cancers and during six for early cancers. Normal stomach wall showed five layers that corresponded to histologic structures. Fourteen of 15 tumors, including nonpalpable early cancers, were localized with ultrasonography. In addition, both depth of penetration and lateral wall extension of the gastric cancers were precisely determined with this technique. Our preliminary results indicate that high-resolution operative ultrasonography may become a diagnostic aid during gastric cancer operations.

Humans↗
PubMed1986

Sonographic evaluation of platelet aggregate retention in a vortex within a simulated venous sinus.

To examine the possible role of venous-valve pockets in enhancing platelet aggregate retention and deposition, in vitro experiments using real-time ultrasonography were performed in a venous-sinus flow model under controlled flow conditions. In each of 10 experiments, adenosine diphosphate (ADP)-induced platelet aggregates in plasma were circulated in both test and control models at upstream shear rates from 60 to 0 sec-1. High-resolution, real-time, B-mode ultrasonography was used to detect and measure the platelet aggregates. Vortex flow was observed in all poststenotic segments, particularly in the sinuses. With reduced shear rates, platelet aggregates increased in size within the vortices and subsequently deposited in the dependent poststenotic tube surface, especially in the sinuses. In conclusion, this study using real-time ultrasonography indicates that the presence of a venous sinus greatly accentuates vortex formation, which, in turn, augments the retention and deposition of platelet aggregates. This relation may provide an explanation for mechanisms that would cause thrombosis to originate in venous-valve pockets.

Adult↗
PubMed1986

Intraoperative ultrasonic imaging of the carotid artery during carotid endarterectomy.

Intraoperative real-time B-mode ultrasonography was used to evaluate the technical results of 155 carotid endarterectomies in 143 patients. Technical defects created as a result of the endarterectomy were detected in 43 of the 155 endarterectomies (27.7%) and included intimal flaps (73% of defects); strictures (18%); and arterial kinks, residual plaque, and intraluminal thrombi (9% collectively). Eleven of the 43 endarterectomy sites (7% of all endarterectomies) were reentered to correct a defect; none of these patients had neurologic deficits, which suggests that reentering an endarterectomy and correcting a defect does not, in and of itself, lead to a higher incidence of stroke. The incidence of stroke in patients with normal results of intraoperative ultrasonography was 3.8%, whereas the incidence of perioperative stroke in those patients with insignificant and thus uncorrected defects was 3.3%; this suggests that intraoperative ultrasonography is sufficiently sensitive to detect defects that, when left uncorrected, do not lead to a higher than usual incidence of stroke. Because intraoperative ultrasonography is safe and highly sensitive, we believe it is the method of choice for assessing the technical results of carotid endarterectomy.

Adult↗
PubMed1985

The effect of extreme acid and alkali changes upon the echogenicity of blood.

The degree of red cell aggregation is dependent upon multiple conditions. The purpose of these experiments was to ultrasonically determine the threshold and reversibility of human red cell aggregation to extreme pH changes at varying shear rates. Real-time B- and A-mode ultrasonography were used to measure echogenicity. Measurements were recorded at original, acidic, and alkaline pH and following return of both acidic and alkaline pH to neutral pH levels. The results showed that 1) neutral red cell suspensions did not become echogenic at any shear rate; 2) acidification produced a shear-related, partly reversible echogenicity; and 3) alkalinization caused a less intense but more shear-resistant and less reversible echogenicity. Alkalinization produced a microscopically discernible greater persistence of intense red cell aggregation. Cell membrane protein loss was detected by electrophoresis.

Adult↗