SUMMARY We investigated the effects of brief intermittent periods of ischemia on myocardial viability. Brief periodic coronary occlusions were produced up to 18 times by inflating and deflating the balloon of an intracoronary #2F catheter for periods of 15, 10 or 5 minutes, followed by 15-minute periods of reperfusion. Creatine kinase (CK) release, triphenyl tetrazolium chloride staining, and light and electron microscopy were used to detect the presence of myocardial necrosis. For the study of CK release, blood was taken from the great cardiac vein and the aorta before and at 5-minute intervals during each left anterior descending coronary occlusion, as well as during and 1, 5, 10 and 15 minutes after balloon deflation. In seven of 24 dogs with 15-minute occlusions, in five of 21 dogs with 10-minute occlusions, and in three of 32 dogs with 5-minute occlusions, small but distinct areas of subendocardial necrosis were present. In all dogs with morphologic proof of necrosis, there was periodic release of CK into the great cardiac vein, which peaked immediately after reperfusion, reflecting CK washout. Thus, brief periods of ischenia, which when single do not cause necrosis, have a cumulative effect and may cause myocardial necrosis. This mechanism of necrosis may be relevant clinically in patients with frequent anginal episodes. Since many dogs of this study did not have any myocardial necrosis, the findings also suggest that intermittent repefdusion has a beneficial effect and may prevent necrosis, even when total occlusion time exceeds 200 minutes.EXPERIMENTAL STUDIES have established that to cause myocardial necrosis, an ischemic injury must be of sufficient duration and severity. Even with the severest ischemia in dogs, the injury must be present for at least 20-30 minutes before necrosis will occur.1 For example, if flow is restored after 15 minutes of ischemia, no myocardial necrosis will be present. ' However, even when ischemia is brief and myocardial necrosis does not occur, there is usually a lengthy delay in return of normal function and metabolism in the injured myocardium.2-Therefore, we evaluated the possibility that brief periods of ischemia before the myocardium has fully recovered from the effects of preceding episodes of ischemia may gradually increase the degree of injury to the point of nonreversibility and necrosis. Methods PreparationThe study was with room air was instituted with a Harvard respirator. Systemic blood pressure was measured through a catheter inserted into the femoral artery. A #5F catheter was inserted through the external jugular vein under fluoroscopic control into the coronary sinus and advanced into the great cardiac vein. The position was verified by injection of contrast material. A #7F Judkins catheter was inserted through the left carotid artery into the ostium of the left anterior descending coronary artery (LAD). A #2F Fogarty catheter was then passed through the lumen of the Judkins catheter and advanced 2-3 cm into the LAD. The Judkins catheter was withdrawn into...

In contrast to pneumoperitoneum, AWL did not alter cardiac function or renal hemodynamics. AWL may be useful in patients with cardiovascular or renal disorders.

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A 71-year-old woman with a solitary mucinous cystic neoplasm of the pancreatic tail complained of back pain. A laproscopic distal pancreatectomy was performed. Laparosonic coagulating shears (LCS) were employed for dissection of the surrounding tissue and transection of the pancreas. The main pancreatic duct was clipped. There was no evidence of bleeding or pancreatic leakage from the transection surface. Pathologic examination showed the tumor to be a mucinous cystadenoma. The postoperative course was uneventful. The LCS was effective in this application.

We report herein the case of a 48-year-old Japanese woman in whom a pancreatic insulinoma was successfully treated by laparoscopic enucleation. The patient presented after developing episodic neurohypoglycemic symptoms, and an insulinoma in the pancreatic tail, 1.0 cm in diameter, was diagnosed by the results of biochemical and radiological examinations. A laparoscopic intraoperative ultrasonogram demonstrated a solitary hypoechogenic tumor in the pancreatic tail. After the tail and body of the pancreas with the spleen were mobilized, laparoscopic enucleation was performed without any complications. The total operative time was 225min and the estimated blood loss was 20 ml. Serial blood sugar measurements demonstrated a sharp rise in blood sugar levels at the time of enucleation. The patient's postoperative course was uneventful, and she was discharged on the seventh postoperative day. She has remained well for 33 months following surgery without any hypoglycemic symptoms.