Biomedical subjects

S Aoyagi

Publications and source records attributed to S Aoyagi.

At least 91 records · Page 5Linked to original sources

PubMed2000

A case of synchronous double cancers of the pancreas and stomach.

Pancreatic cancer carries a poor prognosis, especially invasive ductal carcinoma of the pancreas. We present here the case of a 76-year-old man who developed synchronous double cancers of the stomach and pancreas. He was referred to our hospital in December, 1997, with a provisional diagnosis of carcinoma of the stomach. Laboratory data on admission showed normal levels except for the serum carcinoembryonic antigen level. Abdominal ultrasonography revealed a low echoic mass anterior to the pancreas, suggestive of a nodal metastasis. Intraoperative histological findings from the pancreatic nodule confirmed a primary pancreatic cancer. The diagnosis of double cancers of the stomach and pancreas was made, and subtotal gastrectomy and distal pancreatectomy with lymph nodes dissection were carried out. The histologic sections from the stomach showed a moderately differentiated tubular adenocarcinoma, whereas those from the pancreas showed a well to moderately differentiated tubular adenocarcinoma. Double carcinomas in this association are relatively rare.

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PubMed2000

Coronary artery bypass surgery in a patient with myasthenia gravis.

A 73-year-old man with myasthenia gravis required quadruple coronary artery bypass grafting due to triple-vessel disease. Anesthetic management was performed with general anesthesia using a reduced dose of muscle relaxant with the aid of a neuromuscular transmission monitor. He was extubated 14 hrs after surgery without difficulty under this monitor. His postoperative course was uneventful. A patient with myasthenia gravis who required coronary artery bypass surgery was successfully performed by the deliberate preoperative evaluation of patient's myasthenic and cardiac status, and by the careful perioperative management.

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PubMed2000

Two cases of biliary hemorrhage after percutaneous transhepatic biliary drainage in which transcatheter arterial embolization was effective.

Patient No. 1 was a 66-year-old male who was diagnosed as having cancer of the caput pancreatis, and underwent percutaneous transhepatic biliary drainage (PTBD). Since the tube slipped out, percutaneous transhepatic gallbladder drainage (PTGBD) was performed. After PTGBD, biliary hemorrhage was observed for two to three days, then hemorrhage disappeared and bile flowed smoothly. Since the tube was likely to slip out, the tube was replaced. After replacement of the tube, biliary hemorrhage was noted for two to three days, then spontaneously subsided again. After icterus was reduced, pancreatoduodenectomy was performed. During surgery, a number of massive blood clots were noted in the bile duct. The PTGBD tube was removed, and a transjejunal tube was placed. On the 11th day after the surgery, hemorrhage occurred in the bile duct tube, and the patient went into shock. Emergency abdominal angiography was performed. A false aneurysm was detected in A6 and embolized using a microcoil. After transcatheter arterial embolization (TAE), hemorrhage stopped, and the patient was discharged. Patient No. 2 was a 68-year-old male who was diagnosed as having cholelithiasis and underwent PTBD. On the 21st day after PTBD, biliary hemorrhage occurred and the patient fell in shock status. Emergency abdominal angiography was performed. A false aneurysm was detected in A3 and embolized using a microcoil. After TAE, cholangioscopic lithectomy was performed and the disease alleviated. Thereafter the patient was discharged. It is necessary to consider false aneurysm when biliary hemorrhage occurs after PT(G)BD.

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PubMed2000

A case of duodenal papillary carcinoma complicated by repeated acute pancreatitis.

We present a patient with duodenal papillary carcinoma who repeatedly developed acute pancreatitis preoperatively. The patient was a 65-year-old male. In February 1997, the patient consulted a local hospital due to vomiting, high fever, and jaundice. With the diagnosis of obstructive jaundice, percutaneous transhepatic biliary drainage (PTBD) was performed, revealing a distal bile duct obstruction. Because duodenal papillary carcinoma was diagnosed based on endoscopic findings, the patient was admitted to Kurume University Hospital. Hypotonic duodenography (HDG) disclosed a protruding lesion with an irregular surface in the descending part of the duodenum, resulting in a diagnosis of positive duodenal invasion (du1). Because computed tomography (CT) demonstrated a protruding lesion on the medial side of the second portion of the duodenum, positive pancreatic invasion (panc2) was diagnosed. On March 18 and April 22, sudden abdominal pain, leukocytosis, and an increase in serum amylase were noted. CT revealed that the pancreas was diffusely enlarged, showing an ill-defined boundary between the pancreas and adipose tissue and fluid collection. On CT, the lesion was evaluated as Grade 3 and moderate. For treatment, pancreatic enzyme inhibitors and antibiotics were intravenously injected. Peritoneal perfusion was concomitantly performed during the second treatment. Because symptoms remitted thereafter, a pylorus preserving pancreatoduodenectomy (PpPD) was carried out. The postoperative histologic examination revealed negative pancreatic invasion. Concerning the etiology of acute pancreatitis, not pancreatic invasion, but impaction of the liberated tumor mass in the common canal was considered responsible for the repeated pancreatitis because the tumor showed a cauliflower-like shape.

Acute Disease↗

PubMed2000

A case of intrahepatic gallstone formation around nylon suture for hepatectomy.

A 69-year-old female underwent left lobectomy for hepatolithiasis in February 1994. She was admitted to the Kurume University Hospital in December 1997 because computed tomography (CT) showed calcification in the porta hepatis. Ultrasonography (US) revealed a hyperechoic area with an acoustic shadow in the right hepatic duct. Dilated intrahepatic bile ducts and a mural lucent area in the right hepatic duct were noted on endoscopic retrograde cholangiography (ERC). Although the above findings suggested a diagnosis of recurrent hepatolithiasis, percutaneous transhepatic biliary drainage (PTBD) for biopsy was performed in order to rule out cancer. Biopsy showed no evidence of malignancy. Under a cholangioscope, a tip of a nylon suture was found to be protruding into the bile duct. Although a gallstone had already slipped off, the surface of the nylon suture was covered with biliary sludge. The protruding tip of the nylon suture was considered to be the nucleus of the stone. The tip was removed under cholangioscopy. Postoperative CT confirmed the absence of calcification in the porta hepatis. There has been no recurrence of hepatolithiasis after surgery. Although the formation of gallstones around the core of nylon sutures is very rare, absorbable sutures should be used during surgery of the bile duct because nonabsorbable sutures can become the nucleus of gallstones.

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PubMed2000

Gastric stromal tumor with CD34 immunoreactivity--a case report.

Gastric stromal tumors are the most common mesenchymal tumors, and such submucosal mass lesions of the upper gastrointestinal tract occur frequently. A 54-year-old woman with no major complaint was admitted to our hospital for evaluation of a mass located between the stomach and the pancreas. Abdominal ultrasonography, computed tomography and endoscopic ultrasonography demonstrated a mass lesion which was located near the lesser curvature of the stomach. Selective left gastric arterial angiography revealed a hypervascular mass, and we diagnosed it as a leiomyosarcoma of the stomach. At laparotomy, there was a large solid mass 5 cm in diameter along the minor curvature of the stomach. Tumor resection with partial gastrectomy was performed, and the histological diagnosis was a gastric stromal tumor with CD34 immunoreactivity. We report a case of stromal tumor of the stomach with extramural growth and review the literature.

Antigens, CD34↗

PubMed2000

Successful removal of an infected pacemaker electrode by open heart surgery under extracorporeal circulation.

A 33-year-old male with sick sinus syndrome, who had received a pacemaker implant 18 years earlier, was complicated with a generator infection. Although the infected generator was removed, he was suffered from the recurrent local infection associated with a retained pacemaker lead. After a new pacemaker system implantation from the other side of the subclavian vein, we attempted to remove the lead utilizing a pacemaker removal kit. However, this intervention procedure was unsuccessful, because fibrous adhesions had developed around the lead, accompanied by calcification along its course. As a last resort, we opened the heart under extracorporeal circulation and removed the lead under direct vision. The post-operative course was uneventful. In order to remove a long-term implanted pacemaker lead, the direct surgical procedure with extracorporeal circulation is a favorable mean alternative to conventional intervention techniques.

Adult↗

PubMed2000

Expression levels of thymidine phosphorylase and dihydropyrimidine dehydrogenase in various human tumor tissues.

Thymidine phosphorylase (dThdPase) is the rate-limiting enzyme that metabolizes 5'-deoxy-5-fluorouridine (5'-dFUrd, doxifluridine), an intermediate metabolite of capecitabine, to the active drug 5-fluorouracil (5-FUra), while dihydropyrimidine dehydrogenase (DPD) catabolizes 5-FUra to an inactive molecule. The susceptibility of tumors to fluoropyrimidines is reported to correlate with tumor levels of these enzymes. To obtain some insight into the tumor types susceptible to fluoropyrimidine therapy, we measured expression levels of these two enzymes in various types of human cancer tissues (241 tissue samples) by the ELISA methods. DPD exists in all the cancer types studied, such as bladder, breast, cervical, colorectal, esophageal, gastric, hepatic, pancreatic, prostate, and renal cancers. Among them, the cervical, hepatic, pancreatic, esophageal, and breast cancer tissues expressed high levels of DPD (median >70 U/mg protein), while high concentrations of the dThdPase were expressed in esophageal, cervical, breast, and pancreatic cancers and hepatoma (median >150 U/mg protein). The dThdPase/DPD ratio, which was reported to correlate with the susceptibility of human cancer xenografts to capecitabine, was high in esophageal, renal, breast, colorectal, and gastric cancers (median ratio of >1.5). In any of these three parameters, the inter-patient DPD variability for each cancer type was much larger than the DPD variability among cancer types; highest/lowest ratios for dThdPase, DPD, and dThdPase/DPD were 10-321, 7-513, and 2-293, respectively. These results indicate that measurements of the three parameters, DPD, dThdPase and dThdPase/DPD, would be useful criteria for selecting cancer patients suitable for fluoropyrimidine therapy rather than for selecting cancer types.

Animals↗

PubMed2000

Effects of supplemental L-arginine during warm blood cardioplegia.

OBJECTIVES: Effects of supplemental L-arginine, nitric oxide precursor, during warm blood cardioplegia were assessed in the blood perfused isolated rat heart. METHODS: The isolated hearts were perfused with blood at 37 degrees C from a support rat. After 20 minutes of aerobic perfusion, the hearts were arrested for 60 minutes with warm blood cardioplegia given at 20-minute intervals. This was followed by 60 minutes of reperfusion. The hearts were divided into the following three groups according to the supplemental drugs added to the cardioplegic solution. The control group (n = 10) received standard warm blood cardioplegia. The L-ARG group (n = 10) received warm blood cardioplegia supplemented with L-arginine (3 mmol/l). The L-NAME group (n = 10) received warm blood cardioplegia supplemented with L-arginine (3 mmol/l) and L-nitro-arginine methyl ester, a competitive inhibitor of nitric oxide synthase (1 mmol/l). After 60 minutes of cardioplegic arrest, cardiac function, myocardial metabolism and myocardial release of circulating adhesion molecules were measured during reperfusion. RESULTS: Left ventricular end-diastolic pressure was significantly lower (p<0.05) in the L-ARG group than in the control group and the L-NAME group during reperfusion. Isovolumic left ventricular developed pressure, dp/dt and coronary blood flow were significantly greater (p< 0.05) in the L-ARG group during reperfusion. The L-ARG group resulted in early recovery of lactate metabolism during reperfusion. Myocardial release of circulating intercellular adhesion molecule-1 (ICAM-1) and E-selectin were significantly less (p<0.05) in the L-ARG group at 15 minutes of reperfusion. CONCLUSIONS: The results suggest that augmented nitric oxide by adding L-arginine to warm blood cardioplegia can preserve left ventricular function and ameliorate endothelial inflammation. The technique can be a novel cardioprotective strategy in patients undergoing cardiac surgery.

Animals↗

PubMed2000

[Hemodynamic assessment of the Carpentier-Edwards pericardial valve compared with the St. Jude Medical valve in the aortic position using dobutamine-stress echocardiography].

To assess the hemodynamic performance of the prosthetic valve in the aortic position, we examined dobutamine-stress echocardiography (DSE) to the patients underwent AVR with CEP valve or SJM valve. In 23 mm size, there were no significant differences between CEP group and SJM group in Peak velocity of the aortic jet (PV), peak pressure gradient (PPG) and effective orifice area (EOA). On the other hand, in 21 mm size, PV and PPG of the CEP group were significantly lower than those of the SJM group after DSE. The EOA of the CEP group was significantly larger than that of the SJM group after DSE. Our results suggest that the hemodynamic function of the CEP valve is superior to that of the SJM valve especially in small aortic annuli.

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PubMed2000

A case report of surgical treatment of quadricuspid aortic valve associated with regurgitation.

A case of a 65-year-old woman who had a quadricuspid aortic valve associated with aortic regurgitation is reported. The patient had severe aortic regurgitation and four equally divided aortic cusps. The valve abnormality was detected by a transesophageal echo and an aortography. The incomplete aortic valve was excised and replaced by a St. Jude Medical prosthesis. Although this case had no coronary abnormality, a coronary displacement is often reported in quadricuspid aortic valve cases. In order to perform an operation safely, accurate information which is obtained by a non-invasive examination of the transesoph-ageal echo is quite valuable as it can indicate the need for further preoperative examinations of the coronary arteries.

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PubMed2000

ATS prosthetic valve motion: an in vitro analysis.

BACKGROUND AND AIM OF THE STUDY: We have reported clinical findings that normally functioning open pivot ATS valves did not open completely. In order to analyze features of the ATS valve motion more precisely, in vitro tests were conducted. METHODS: Opening angles and pressure gradients of the ATS valve were measured and compared with those of the St. Jude Medical (SJM) valve under steady flow, but with various outlet configurations. Second, opening angles of the two valves were measured under pulsatile conditions in two different outflow configurations: (i) a 'straight outlet' where the leaflets did not extend into the tapering outflow chamber, and (ii) an 'abrupt enlargement outlet' where the leaflets extended directly into the enlarged outflow space. Third, flow visualization studies were made under steady flow conditions in the straight and abrupt enlargement outlet conduits, respectively. RESULTS: Under steady flow conditions, opening of the ATS valve was restricted in most outflow configurations; only when the outlet angle was 0 degrees did the valve open fully. The SJM valve opened completely in all downstream configurations. Despite restricted opening in the ATS valve, the pressure gradient was similar in both valves. Under pulsatile conditions, both valves opened fully in the straight outlet; however, in the abrupt enlargement outlet the ATS valve opened incompletely and the SJM valve completely. Substantial turbulent flow was observed at the outside of the leaflet and corners of the conduit, notably with the ATS valve. CONCLUSION: This study showed that the ATS valve did not open fully except when the outflow was straight, and the leaflet did not extend into an enlarged downstream chamber. Structural features of the ATS, such as its axis being located close to the straight edge and its leaflets extending further downstream from the ring orifice, may cause this unique valve behavior.

Heart Valve Prosthesis↗

PubMed2000

[Indication and limitation of microwave coagulation therapy for stage IV-A hepatocellular carcinoma].

Patients with stage IV-A hepatocellular carcinoma have been considered to have dismal prognosis. However, among them there are many of patients with multiple carcinoma of multicentric origin, whose prognosis is not necessarily poor. For treatment of multiple carcinoma, preoperative evaluation for the malignant aggressiveness of each nodule, and for liver function impairment is essential. Although hepatic resection has a high curability, resection sometimes impair long term survival because of postoperative deterioration of liver function. In this point, heat ablation therapy such as microwave coagulation therapy is favorable treatment, and for some nodules at early stage heat ablation therapy would have a sufficient curability to achieve long term survival. Authors decide on the selection of treatment (resection or heat ablation therapy) according to preoperative evaluation for the malignant aggressiveness by diagnosis of tumor gross type, and for the degree of liver impairment by serum hyaruronic acid level.

Adult↗

PubMed1999

Nonfunctioning islet cell carcinoma of the pancreas: an evaluation of seven patients who underwent resection followed by long-term survival.

Islet cell carcinoma of the pancreas is a rare, indolent malignancy associated with a higher resectability rate and better survival than ductal carcinoma. This retrospective study presents the results of surgical treatment for nonfunctioning islet cell carcinoma of the pancreas in seven patients diagnosed and treated at Kurume University Hospital. There were two men and five women, with an average age of 54 years. Of the five tumors, four were located in the head of the pancreas, and the other three tumors were located in the body or tail of the pancreas. Epigastric pain was frequently the primary clinical symptom. By the time of diagnosis, four of the patients had regional disease, one of whom had lymph node and liver metastases, and one, liver metastases. Another patients was found to have lymph node metastases intraoperatively. Only one of the patients died of recurrent cancer, 21 years after the original operation. All of the patients who had liver metastases at the time of initial surgical treatment are now living at home. Thus, we conclude that nonfunctioning islet cell carcinomas are slow-growing tumors with a good prognosis if the main tumors and metastatic lesions are removed.

Adult↗

PubMed1999

Nesidioblastosis with hyperinsulinemic hypoglycemia in adults: report of two cases.

We report herein the cases of two women, aged 34 years and 39 years, respectively, found to have hyperinsulinemic hypoglycemia after presenting with a history of episodes of temporary loss of consciousness, nausea, and fainting. Under the suspected diagnosis of insulinoma, localization procedures were carried out, but no tumor was found. In both patients, a definite gradient in insulin concentration was found in the pancreas by percutaneous transhepatic or intraoperative portal venous sampling, and a misdiagnosis of insulinoma of the pancreatic body was made. During exploratory laparotomy no tumor was palpable in the pancreas, and intraoperative ultrasonography showed no low echoic mass in the pancreas. A distal pancreatectomy was performed in both patients, and histopathological examination of the resected specimens revealed graded slight hyperplasia of the islet cells.

Adult↗

PubMed1999

Gastric enterochromaffin-like-cell tumor with liver and splenic metastases.

We report a patient with gastric enterochromaffin-like-cell tumor with liver and splenic metastases. He was 68 years old and presented with major complaints of epigastric pain and weight loss. Under the diagnosis of gastric carcinoma with liver metastasis, total gastrectomy with splenectomy and lateral segmentectomy of the liver was performed. Intraoperative findings resulted in a diagnosis of adenocarcinoma T3N2P0H1, in stage IVa. Histological examination of the resected specimens showed a well differentiated neuroendocrine carcinoma (enterochromaffin-like-cell tumor) with liver and splenic metastasis which demonstrated high-grade lymphatic and vascular invasion. There was no lymph node metastasis. The tumor cells in the stomach, liver and spleen were immunoreactive for chromogranin A and Grimelius--positive. We review the literature, as well as presenting this case report.

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PubMed1999

Concentric wear of the Delrin disc in a Bjork-Shiley heart valve prosthesis: report of two cases.

We report herein the cases of two patients who received replacement of aortic Bjork-Shiley Delrin (BSD) valves that had been implanted for over 20 years following the development of aortic regurgitation (AR) resulting from wear of a Delrin disc. Case 1 was a 61-year-old woman in whom echocardiography revealed marked left ventricular dilatation and moderate AR 23 years after an aortic valve replacement (AVR) with a 21-mm BSD valve. Case 2 was a 51-year-old woman in whom echocardiography revealed marked dilation of the right atrium and moderate AR 23 years and 8 months after an AVR with a 21-mm BSD valve, as well as a mitral valve replacement with a 3M Starr-Edwards (SE) ball valve and tricuspid annuloplasty. In both patients, the BSD valves were replaced with other mechanical valves at reoperation. Examination of the explanted BSD valves showed that the Delrin discs contained increases in the radial gaps and strut indentation grooves on the inflow and outflow surfaces. The type and magnitude of the wear on the Delrin discs in these valves were consistent with data reported in the literature for this valve design after similar implant duration.

Aortic Valve↗

PubMed1999

Inhibitory effect of milrinone on cytokine production after cardiopulmonary bypass.

BACKGROUND: It has been suggested that cyclic adenosine monophosphate-elevating agents suppress cytokine production. To evaluate the effects of milrinone, a phosphodiesterase III inhibitor, on cytokine production after cardiopulmonary bypass, we conducted a prospective randomized study. METHODS: Twenty-four patients undergoing coronary artery bypass grafting were randomized to receive either milrinone treatment (milrinone, n = 12) or no milrinone treatment (control, n = 12). Administration of milrinone (0.5 microg x kg(-1) x min(-1)) was started after induction of anesthesia and was continued for 24 hours. Blood samples for determination of plasma cyclic adenosine monophosphate, tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, and interleukin-8 levels were collected perioperatively. RESULTS: No significant differences were observed in tumor necrosis factor-alpha and interleukin-8 levels between the groups. Interleukin-1beta and interleukin-6 levels after cardiopulmonary bypass were significantly (p < 0.05) lower in the milrinone group than in the control group. Plasma levels of cyclic adenosine monophosphate increased significantly (p < 0.05) after the administration of milrinone and the levels correlated inversely (r = -0.55, p < 0.01) with interleukin-6 levels. CONCLUSIONS: The results indicate that milrinone suppresses cytokine production by elevating cyclic adenosine monophosphate levels in patients undergoing cardiopulmonary bypass. With its positive inotropic and vasodilator activities, milrinone may have antiinflammatory effects.

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