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Classical techniques of reconstruction of large eyelid defects require temporary occlusion of the eye. Use of a free autogenous tarsoconjunctival graft with a skin-muscle flap is described. Twelve patients were operated with ten good, two fair, and no poor results. This method can be used to repair medial, lateral, and central defects of the upper and lower eyelids.

✓ In 21 cats the pressure in the occluded middle cerebral artery (MCA) was recorded by way of a catheter, introduced in the most proximal portion of this artery by way of the transorbital approach. The effect of temporary occlusion of the ipsilateral and contralateral common carotid artery on the pressure in the occluded MCA was studied. The results seem to prove the existence of the so-called “interhemispheric steal” syndrome.

A left gastric venacaval shunt for esophageal varices was performed in six patients in attempts to selectively decrease left gastric venous pressure without decreasing portal venous pressure. The left gastric venous pressure decreased from 140–390 mmH2O to 140–200 mmH2O after the left gastric venacaval shunt, while the portal venous pressure remained at 140–370 mmH2O, postoperatively. Even when the portal venous pressure increased up to 320–400 mmH2O with a temporary occlusion of the portal vein, there were no significant changes in the left gastric venous pressure. Five patients are doing well, one to 36 months postoperatively. One patient died of hepatic failure with bleeding on the 21 st postoperative day. The left gastric venacaval shunt decreased the incidence of rebleeding and prevented postoperative hepatoencephalopathy and hepatic failure.

Chronic obstructive pancreatitis-like histological and biochemical alterations were provoked in male Wistar rats with Ethibloc occlusion of the common bile duct and the main pancreatic ducts. After the disappearance of the glue from the ducts, a gradual and almost total recovery was demonstrated during a 2-month observation period. About 12 g/kg of alcohol (20% vol/vol) given daily by gastric intubation and ad libitum intake inhibited the recovery of pancreatic weight and enzyme contents in the occluded rats, and within a 2-month period chronic calcifying-type pancreatitis became evident with some signs of remaining obstructive pancreatitis-like lesions. Cessation of alcohol administration after 2 months resulted in a recovery of pancreatic weight and enzyme contents, although morphological regeneration was less pronounced and calcification remained visible in some rats. A 50% raw soy flour diet provoked some further changes in the proportion of enzymes without any supplementary increases of pancreatic weight and protein content. This animal model of chronic pancreatitis demonstrates that chronic obstructive and calcifying pancreatitis can appear together and earlier if the etiological factors act in combination. Suppression of pancreatic regeneration by alcohol seems to be necessary to maintain chronic pancreatitis-like lesions and to develop calcification.

SummaryExperiments on monkeys show that in this primate, temporary occlusion of the blood supply to the legs does not cause any signs of shock until the circulation through the damaged leg is reestablished. Then severe shock ensues even before any significant amount of fluid can be lost from the blood into the damaged area. This observation is incompatible with the dehydration theory of shock.Blood taken from the vein of an extremity which was damaged by temporary occlusion of its blood supply does not prove more toxic when assayed on the adrenalectomized mouse than blood coming from an intact extremity. This observation is incompatible with the toxic theory of shock.Experiments on the rat and cat indicate that the sugar concentration of the blood coming from a damaged extremity is significantly below the corresponding values in normal venous blood, conversely the hemoglobin and N.P.N. concentration is above normal in blood which passed through the damaged area. It appears that damaged tissues remove cert...

Absteact: Studies were made on human cadavers and on living dogs whereby the bleeding of experimental aneurysms of the internal carotid artery was stopped by distending a balloon at the mouth of the aneurysm. The balloon was introduced intra-arterially at a point distant from the aneurysm and guided to the bleeding site via a system of catheters. Although many obvious technical problems remain to be surmounted, these preliminary observations support the feasibility of an intra-arterial approach to the therapy of aneurysms of the internal carotid artery. The concept of temporary occlusion of the aneurysmal mouth by intra-arterial inflation of a cannula-borne balloon merits further investigation.

In rats pretreated with 2α-methyl-9α-chlorocortisol (Me-Cl-COL) and NaH2PO4, temporary occlusion of the pylorus regularly elicits acute, massive myocardial necroses and nephrocalcinosis, as well as a high mortality. The possible clinical implications of this fact, as regards the pathogenetic role of acute gastrointestinal disorders in the production of cardiac infarcts, is discussed.

Occlusion of the aorta of the rat between the fourth and fifth thoracic vertebrae produces focal ischemic lesions of the gray matter of the lumbar spinal cord. Two types of lesions can be distinguished.

In dog and monkey permanent occlusion of the middle cerebral artery (abbreviated to m.c.a. herein) ordinarily produces a lateralized neurological deficit, the degree of impairment varying from one animal to the next. 4,9,10 Rosomoff 10 reported that of 15 dogs in which the artery was occluded under normothermic conditions, 8 developed severe deficit, 6 lesser but significant involvement, and one none at all. Temporary occlusion can also produce neurological symptoms. In the monkey 50 minutes is required to yield an impairment equivalent to that produced by permanent occlusion. 4 Changes in the brain's electrical activity during and for short intervals after an experimental occlusion are also variable. 5,6 Pertinent to this study is the fact that occlusion does not invariably provoke electrical changes. 6 Both the electrocorticogram (ECG) and steady potential (SP) have been studied. 6 The latter refers to relatively sustained departures from the resting potential recorded between a

1.In vivo injections of neoprene latex demonstrated intrarenal vasoconstriction in eight of nine rabbits previously subjected to temporary occlusion of the left renal artery. Constriction of all the intrarenal arteries was demonstrated after injection at pressures below 100 mm. Hg. At higher injection pressures constriction was evidently only in the peripheral cortex.

A study was made on the blood-brain barrier (BBB) to protein tracers in focal cerebral ischemia and infarction caused by permanent or temporary occlusion of the middle cerebral artery (MCA) in the rhesus monkey.

Pressure pulses were recorded simultaneously at the aortic/external iliac junction and in the abdominal aorta of six normal dogs at a distance 7—10 cm upstream of the junction. The matched abdominal aortic equitrifurcation was then transformed, in vivo, to an unmatched equibifurcation by temporary occlusion of the central branch and the pressure recording procedure repeated. An increase in the oscillatory pressure amplitudes at the junction was observed as a result of the unmatching procedure. At the upstream site the amplitude increase was similar to the junction site for only the first two harmonics of the pressure pulse. These changes were interpreted as being due to increased reflection from the unmatched junction and alteration in the peripherally reflected pressure waves reaching the aorta.

1. 1. Four patients successfully treated by thrombectomy for acute progressive iliofemoral or inferior vena caval thrombosis are presented. 2. 2. General anesthesia and temporary occlusion of the inferior vena cava or common iliac veins were employed in each patient. 3. 3. Our experience suggests that early thrombectomy for thrombosis of major veins is a valuable procedure which deserves wide-spread adoption.

1. Generalised intrarenal vasoconstriction was demonstrated by means ofin vivo injections of neoprene latex in three of four rabbits, previously subjected to temporary occlusion of the renal artery. The fourth kidney showed evidence of a juxtamedullary circulatory shunt.

Functioning collateral channels were uniformly shown following temporary unilateral renal artery occlusion lasting 30–90 minutes in nephrectomized dogs. The kidneys decreased in size, with slower blood flow, a protracted, irregular nephrogram, and early visualization of veins. Contrast injection during occlusion was associated with profound renal damage in the dogs studied. Unintentional renal artery occlusion in man during selective renal arteriography is equally hazardous. It may be avoided by careful, continuous monitoring of blood pressure through the selective catheter, visual evidence of rapid disappearance of the test injectate, and demonstration of good backflow from the catheter.

1. 1. A method is presented by which the electrocardiographic changes due to experimental coronary occlusion may be differentiated from those caused by the associated postoperative pericarditis. 2. 2. It is shown that the changes in the final ventricular deflections which are due to experimental, temporary, coronary occlusions of fifty minutes, or less, vanish completely within thirty minutes after cessation of occlusion, and that the changes which appear on and after the first postoperative day are caused by local postoperative pericarditis. 3. 3. Other factors being equal, the duration of the electrocardiographic changes which immediately follow cessation of occlusions of fifty minutes, or less, is directly proportional to the duration of the occlusion. 4. 4. There are no differences in the magnitude or in the kind of electrocardiographic changes which are produced by acute local ventricular ischemia and injury, on the one hand, and by local postoperative pericarditis, on the other. The former occur during, and for a brief time after, temporary occlusion. For the most part, the latter occur on and after the first postoperative day. The site of generation of the electrical effects which account for the two etiologically different groups of changes is different, i.e., the electrical effects associated with occlusion are generated in the muscle ordinarily irrigated by the occluded artery, whereas those associated with postoperative pericarditis are generated by the muscle adjacent to the local epicarditis which results primarily from the trauma of dissection of the coronary artery and from the trauma caused by the sutures which are used to close the pericardial sac. 5. 5. These observations differ decidedly from those of others, 8–10 . We ascribe the differences to the use, by others, of extremity leads only. It is important not to rely entirely upon extremity leads for an evaluation of the electrocardiographic changes which occur in association with animal experimentation.

SummaryDiabetes was prevented in 9 of 10 rabbits given alloxan by temporary occlusion of the celiac and superior mesenteric arteries. The remaining animal developed moderate, delayed diabetes with mild histological changes in the islets of Langerhans.Severe hypoglycemia was observed in several of the rabbits which failed to develop diabetes and which failed to show any histological change in the islets of Langerhans or the liver when examined at 2 to IS days.These experiments indicate that alloxan diabetes is pancreatic in origin but suggest that the hypoglycemic phase is either extrapancreatic in origin or may be produced by the action of very small quantities of alloxan insufficient to produce detectable changes in the islets of Langerhans.

In certain diagnostic entities temporary occlusion of the pulmonary veins during cardiopulmonary bypass essentially eliminates the left ventricular return of blood. This, in turn, improves visualization of the operative field and enhances myocardial hypothermia by preventing rewarming of the left ventricle to the perfusate temperature. Two methods of easily accomplishing pulmonary vein clamping are described.

Surgical exploration of the nasal cavity and paranasal sinuses of dogs is often necessary to diagnose or treat conditions causing complete or partial nasal obstruction. Hemorrhage may obscure exploration and be detrimental to the patient. Temporary occlusion of both common carotid arteries reduces blood loss and enhances visualization during rhinotomy. Temporary bilateral common carotid artery occlusion was performed on 15 dogs subjected to nasal exploration. No obvious detrimental effects were noted.

Two cases of extracranial internal carotid artery aneurysms are presented. In each case the cranial end of the aneurysm was in contact with the base of the skull. Ligation of the internal carotid artery was performed in the first case. Temporary occlusion of the distal internal carotid artery by means of a Fogarty catheter allowed resection with end-to-end anastomosis in the second case.

Five patients underwent cerebral revascularization operations during which Biemer clips were used to occlude temporarily a branch of the middle cerebral artery. Postoperative angiograms revealed stenoses at the sites where the clips were applied. Excessive clip closing forces may have caused significant endothelial injury, which then produced the stenoses. Clips that exert a minimal occlusive force would avoid this response and are recommended for temporary occlusion of cortical arteries.

Summary1. Compression of the coronary vessels and immediately adjacent tissue as descrilml caused pain without exception, sometimes salivation, vomiting in one case, a disturbance of respiration, “acute dilatation” of the heart and various changes in the electrocardiogram. Symptoms have not been produced by localized compression and tearing of the myocardium or pericardium. This may be due to a high threshold of problematical pain endings in the normal cardiac muscle and pericardium.2. Severance of the vagi has not interfered with transmission of pain impulses in 2 dogs.3. Removal of the left stellate ganglion has prevented the transmission of pain impulses in 2 dogs but salivation occurrecl in one of the 2.4. A prompt fall of blood pressure occurred in all acute experiments on compression of the coronary vessels as described. Section of the vagi usually prevented this fall in blood pressure.5. Fall of blood pressure, cardiac dilatation and cardiac irritability are increased by moderate cyanosis (anoxemia).

The occlusion of the bilateral common carotid arteries (CCA) in Mongolian gerbil causes severe telencephalic ischemia [4, 5], and the temporary occlusion of bilateral CCA has been used as a good model for reversible and/or irreversible global cerebral ischemia [2]. There have been no studies on the changes in water content of brain in association with the duration of ischemic period or on the relationship between the changes and neurologic deficits following transient global cerebral ischemia in this animal. In the present study we evaluated the changes in water content of four brain regions and the neurologic deficits in the same animals, and investigated the relationship between these two variables.

Prevention of nasal air flow by temporary occlusion of the nares significantly lowered the convulsive threshold to lidocaine and pentylenetetrazol in the rat. This result indicates that olfactory stimulation is not a contributing factor in convulsions induced by local anesthetic agents such as lidocaine.

The immediate evolution of changes in serum bilirubin and alkaline phosphatase levels during and after brief temporary occlusion (12 hours or less) of the main bile duct was studied in the rat. Transient obstruction of the main bile duct of more than one hour was characterized by a simultaneous increase in serum levels of both bilirubin and alkaline phosphatase. The time required for return to normal values was less for bilirubin than the duration of a brief obstruction and was more prolonged for alkaline phosphatase than the duration of obstruction. In obstruction of four or more hours, it was rare to find an isolated elevation of serum bilirubin; this occurred when the control value for alkaline phosphatase levels was low and their relative increase was obscured. Thus, an isolated increase in the serum bilirubin level is infrequently compatible with obstruction of the bile duct, even when transient and of brief duration. Conversely, isolated elevation of serum alkaline phosphatase levels in an acute abdominal syndrome may indicate relieved biliary obstruction.

A unique opportunity presented itself for a morphologic study of experimental unilateral acute renal failure (ARF) in male rats. The ARF had been induced in the rats by temporary occlusion (1 h) of the left renal artery. Twenty-nine rats were divided into subsets as follows: 2–3 h, 24 h, 1 week, 2, 4, 8, and 12 weeks following release of occlusion. Microdissection showed a heterogeneous population of abnormally structured proximal tubules in which the regressive lesions of tubular necrosis were combined with the progressive reaction of repair. The lesions demonstrated are reminiscent of those which have been described in ARFin the human and in experimental animals. Many proximal tubules in the 2- to 3-hour subset presented 1–3 disruptive lesions (DLs) while greater numbers of proximal tubules from the 24-hour group presented 1–5 DLs. Many proximal tubules presented no DLs, but nearly all from the 24-hour subset (97–100%) displayed a squamate appearance which paralleled and was caused by acute tubular necrosis. At 1 week, a dilated pars recta was common, but by this time, the squamate pattern had disappeared. Many casts were present. At 2 weeks, many fewer casts were present in proximal tubules and none were seen at 4, 8 or 12 weeks. The nephrons, particularly the proximal tubules, presented a variety of structural alterations at 2, 4, 8 and 12 weeks. Changes of special interest include (1) the presence of swan-necks; (2) a distinctive squamate appearance of the proximal tubules in the animals killed at 24 h; (3) a spiral, curled appearance caused by differential hyperplasia in animals at 4, 8 and 12 weeks, and (4) a tendency for ischemic lesions to involve all layers of the renal cortex.

Oxygen-derived free radicals have been implicated in a wide variety of disease states [1,2] and have been postulated to mediate an element of cerebral ischemic injury. We tested the hypothesis that neutralization of oxygen free radicals using superoxide dismutase (SOD) ameliorates the cerebral ischemic injury produced by temporary occlusion of the middle cerebral artery.

In the majority of cases TIAs are due to emboli originating from atherosclerotic plaques and/or thrombi located at the carotid bifurcation. The embolization leads to a temporary occlusion of ophthalmic branches and/or of one or more intracranial branches generally in the territory of the middle cerebral artery.

Thirty specially designed 4 French pigtail white Teflon catheters 50 cm in length were utilized for angiography using the retrograde arterial approach in 26 infants and children. Angiographic opacification was considered very satisfactory. Apart from one episode of temporary occlusion of the right coronary artery ostium, there were no other significant complications. The catheters were introduced percutaneously in 21 instances and distal pulses were palpable in 18 patients by the second day after catheterization. At postcatheterization testing with increasing volumes and flow rates, the first rupture occurred, delivering 13 ml at 13 ml/second. On testing an additional 15 catheters using fixed volumes of 5, 10, and 15 ml at increasing flow rates, rupture first occurred at 34, 22, and 18 ml/second, respectively. We conclude that this small catheter is relatively safe and satisfactory for the retrograde arterial approach in the study of infants and children.

In “dry limb” femoral arteriography, temporary occlusion of the external iliac artery is induced by means of a percutaneously introduced balloon in order to control the flow of blood and contrast material, resulting in simultaneous opacification of all of the vessels of the lower extremity.

The Biemer and Yasargil microvascular clips that are currently available commercially can traumatize the vascular endothelium. In an effort to resolve this problem, both clip designs were structurally modified by changing the length, width, and surface of the clip blades in various ways. Also, the occlusion force of the clips was set at either 15 or 30 g. Studies on the carotid arteries of 140 rats showed a correlation between the structural and mechanical alterations of the clips and the degree of endothelial trauma produced by temporary occlusion for 1 hour. The most favorable results were obtained with a Biemer clip that had long, wide, smooth blades and an occluding force of 15 g.

We present our early experience in the treatment of cutaneous capillary-venous malformations using a new fibrosing agent called Ethibloc. Superselective angiography was used to delineate the vascular anomaly and effect temporary occlusion. Whenever possible, compression of venous outflow also was used, while the sclerosing agent was injected directly into the malformation by percutaneous puncture. Sixteen patients with capillary-venous malformations have been treated with this agent since 1979. A mild local inflammatory reaction was noted in some cases; there were no instances of skin necrosis. In 10 patients, the fibrosed vascular malformation was excised, and in 6 patients, the area of vascular anomaly decompressed to such a degree that resection was unnecessary.

✓ A case of a giant anterior cerebral artery fusiform aneurysm is presented. The lesion was treated by primary excision of the involved segment with an end-to-end anastomosis of the proximal-distal segments of the anterior cerebral artery. It is believed that this technique has not been reported previously for lesions involving major intracranial arteries.

One of the great difficulties in the development of surgery of parenchymal organs is the control of bleeding during dissection. This can be accomplished by cutting within intersegmental planes or by temporary occlusion of the vessels. Selective separation of tissue from vessels and fibrous structures is possible by focused ultrasonic energy (e.g., CUSA-System), which has found increasing application in liver and brain surgery. Another possibility of selective dissection is the method of water-jet cutting.

Reperfusion after severe cerebral ischemia usually produces disruption of the blood-brain barrier (BBB) and causes marked brain edema. However, the mechanism responsible for the increase in vascular permeability is not well understood.

A method was developed to predict the severity of cerebral ischemia before permanent occlusion of a common carotid artery in gerbils by observing the diameter and appearance of the artery after temporary occlusion and observing clinical signs after permanent occlusion. The severity of cerebral ischemia was confirmed by a sensitive immunohistochemical method and measurement of focal cerebral blood flow after 30 minutes' ischemia. All gerbils with greater than 40% reduction of the diameter and a white arterial margin distal to temporary occlusion developed severe neurologic signs following permanent occlusion, but no gerbils with reduction of less than 30% and a red arterial margin developed neurologic signs. With the cumulative neurologic score, gerbils could be divided into classes with no, mild, moderate, and severe symptoms, mostly after 10 minutes. Severely symptomatic gerbils were identified in 3 minutes. Extensive ischemic damage was observed in severely symptomatic gerbils, but no immunohistochemical lesion was detected in mildly symptomatic gerbils. Cerebral blood flow was markedly reduced in severely symptomatic gerbils but more selectively reduced in the cortical structures of moderately symptomatic gerbils. This prediction method is useful for investigating early cerebral ischemia and for evaluating the effectiveness of pharmacologic agents.

Technique of selective renal occlusion phlebography is described. For the temporary occlusion of the renal vein a Swan-Ganz or Dotter-Lucas balloon catheter are used. The balloon catheter is directed into the renal vein using a Desilets-Hoffman or EDSLAB introducer. Occlusion of the renal vein is achieved by insufflation of 2–3 ml. air into the balloon of the catheter. Selective renal occlusion phlebography leads to optimal retrograde opacification of the renal venous system.

Microvascular procedures for cerebral aneurysms or revascularization of small arteries require the application of microvascular clips. In 1911, CUSHING [1] became the first to describe the application of vascular clips for the occlusion of bleeding cerebral vessels. Increasingly authors are recommending the application of some temporary clips before preparation and occlusion of an aneurysm without regard to possible vessel wall lesions being caused by the clips themselves. To ensure the successful performance of the finest surgical techniques these clips are expected to bring about the temporary occlusion of a cerebral vessel combined with minimal vessel wall lesion. We therefore set out to study the effects of different microvascular clips with a diameter of 1–2 mm on the vessel wall and measured blood flow in the temporarily clipped arteries.

The respective importance of flow and cellular viability in determining initial myocardial thallium uptake was studied in reperfused and nonreperfused experimental myocardial infarction. Open-chest dogs were subjected to permanent coronary artery occlusion of 70-minute (n = 3) or 5-hour duration (n = 5), or to a 3-hour temporary occlusion followed by reflow (n = 14). Thallium uptake 10 minutes after intravenous injection was compared directly with radioactive microspheres in myocardial samples from excised hearts. Triphenyl tetrazolium chloride staining was used to differentiate necrotic and viable samples with confirmation by electron microscopy. In nonreperfused infarcts, thallium uptake occurred despite necrosis, and a close correlation was found between thallium uptake and regional myocardial blood flow. In reperfused infarcts, thallium uptake again occurred, but was reduced relative to flow in necrotic myocardium and, to a lesser extent, in reperfused viable areas. However, because of the high levels of reflow, actual thallium uptake was often more than 50% of normal in reperfused necrotic regions. This study demonstrates that the presence of thallium uptake is an unreliable indicator of myocardial injury and that reperfused necrotic tissue may have remarkably high levels of thallium uptake.

The effects of nizofenone on ischemic cerebral edema in Mongolian gerbils were compared with those of pentobarbital (PBT). Water content, used as an index of cerebral edema, was calculated from the wet and dry weights of each hemisphere. In the sensitive gerbils subjected to permanent occlusion of the right common carotid artery, water content of the right hemisphere increased by about 6% at 24 hr after ischemia. In the animals treated with nizofenone (30 mg/kg i.p.) and PBT (60 mg/kg i.p.), water content was significantly lower than that of the control group at 24 hr and 1.5-24 hr after ischemia, respectively. In the sensitive gerbils subjected to temporary occlusion of the right common carotid artery for 60 min, water content of the right hemisphere increased gradually by about 5% at 72 hr after recirculation. In the animals treated with nizofenone (30 mg/kg i.p.) and PBT (60 mg/kg i.p.), water content was significantly lower than that of the control group at 24-72 hr and 1.5-72 hr after recirculation, respectively. Nizofenone became effective in lowering brain water content after 24 hr following ischemia. On the other hand, PBT was effective from an early stage of ischemic cerebral edema. Brain edema following an ischemic injury is considered to be initially of the cytotoxic type, subsequently changing into the vasogenic type. The above results suggest that nizofenone may be effective in ameliorating ischemic cerebral edema, particularly vasogenic edema, and that this may be partially related to its cerebral protective action.

Six commonly used surgical clips (Kleinert-Kutz, PivotTM Vari-Angle, Yasargil, Biemer, and Acland) that have been designated by their manufacturer as being suitable for temporary occlusion were studied in terms of their mechanical and metallurgical properties. Opening and closing forces were determined for all of the clips. Significant variations in clip force with respect to blade gap were found in all of the pivot-type clips. Metallurgical testing showed that all six clips exhibited properties that contraindicate long-term implantation.