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A total of 231 patients with atheromatous ulcerations of the carotid artery and obstructions due to critically stenotic plaques or kinks underwent reconstructive surgery mainly of the internal carotid artery, under general anesthesia, normocarbia, and without increasing the systemic blood pressure. Continuous electroencephalography and phot pulses from the cutaneous territories of the internal and the external carotid arteries were used to monitor 250 carotid operations. An intraoperative test, clamping of the common carotid artery and its two branches for 3 min, was performed on each patient. An internal shunt was routinely used in 18 patients. In the remaining 232 operations, an internal shunt was selectively used in only 13 of the 15 patients in whom there was focal showing on the EEG and/or a reduction in the amplitude of the ipsilateral supraorbital pulses to less than 25% of their preclamping values. In the group in which no shunt was used, the duration of the carotid clamping varied from 6 to 59 min, with a mean of 26 min. Seven patients died, but death was related to brain ischemia during surgery in only two. There were no ischemic neurological complications, except in the patients who died. This results in a mortality and morbidity rate of 0.8%. In those patients in whom a shunt was used, CCPPG recordings clearly indicated obstruction of the shunt during surgery. Thrombotic occlusions of the distal end of the shunt in one case and of the repaired vessel in another two were diagnosed. Electroencephalographic and CCPPG monitoring provided useful information of the state of cerebral function, the level of anesthesia, and the occurrence of cardiac dysrhythmia or hypotension and its effect on brain circulation. It is believed that this monitoring technique greatly contributed to the decreased mortality and morbidity in our series.

Massive coagulopathy and bleeding continues to play a major role in the operative mortality and perioperative multi-system failure of patients requiring elective thoracoabdominal aneurysm repair. It was the purpose of this study to determine the coagulation defect that occurs with supraceliac aortic clamping and the effects of increasing aortic cross-clamp time (AXCT) on the coagulation system and its recovery. Through a standard thoracoabdominal incision, 16 mongrel dogs had their aortas cross-clamped simultaneously just above the diaphragm and at the aortic bifurcation. Animals were divided into four groups of four animals each; sham operation, 30 minute AXCT, 60 minute AXCT, and 90 minute AXCT. Central venous blood was sampled prior to aortic cross clamping (AXC), during AXC and 1 hour, 2 hours, 5 hours, 7 hours, 12 hours, and 24 hours after the clamp was removed. All samples were assayed for platelets, fibrinogen, fibrin split products, prothrombin time (PT) and partial thromboplastin time (PTT). Platelets and fibrinogen decreased as PT and PTT increased with increasing AXCT consistent with disseminated intravascular coagulation (DIC) (P less than .001). Fibrin split products were positive in the 90 minute AXCT group only. The drop in platelets was greater for increasing AXCT and continued to fall in the 30, 60 and 90 minute AXCT groups at 24 hours (p less than .001). Fibrinogen dropped to the lowest levels between two and twelve hours after AXC and returned to normal at twenty-four hours in the 60 and 90 minute AXCT groups (p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Five cases of thoracoabdominal aneurysms are reviewed. These cases were observed during the last 10 years and their incidence was 4% of all aortic aneurysms admitted in the same period. In all the patients the Crawford's technique by graft inclusion with visceral vessel reattachment by direct suture, without by-pass, was adopted. Of the five patients, two underwent elective surgery and three emergency surgery. While the mortality rate in the patients operated on election was 0%, on emergency it was 66,6%.

Haemodynamic changes due to aortic cross-clamping were examined in 18 patients. It has been shown that the distal occlusion of the abdominal aorta induces an increased impedance to ejection. Because the mechanisms controlling the auto-regulation of cardiac output and the circulatory reflexes are damped by anaesthesia, the augmentation of resistance is not followed by any increase in contractility or vasomotor tone and thus the cardiac output falls. Patients with chronic obstructive disease (Leriche) did not differ significantly from subjects with more acute obstruction (aneurysm), though the latter have a tendency to show more important changes in their haemodynamic response.

Presently we favor heparinless femorofemoral venoarterial bypass for all descending thoracic aneurysm resections. The advantages are minimal blood loss due to the absence of heparin, ease of insertion, especially in large aneurysms where it would be difficult to insert a temporary shunt, distal aortic perfusion, possibly a safety factor in preventing spinal cord and visceral ischemia, and prevention of left heart overload and myocardial failure. In acute traumatic ruptures, simple aortic cross clamping is a suitable alternative. It is safe and can be carried out expeditiously in any community hospital where bypass facilities may not be available. Proximal hypertension can be controlled pharmacologically. We have also used this successfully in ruptured atherosclerotic aneurysms. We have no experience with temporary tridodecylmethylamonium (TDMAC) shunts; several groups have used them successfully. We believe they may be difficult to insert in the proximal aorta with a large mediastinal hematoma or extensive aneurysm. Cannulation of the left ventricular apex necessitates cardiac manipulation and may produce effective aortic valve insufficiency. In patients with aortoesophageal and bronchoesophageal fistula, permanent extrathoracic bypass is preferable to a prosthetic graft in a contaminated field. We propose using a permanent bypass with a no. 10 or 12 right axillofemoral bypass. Our experience is limited to only two patients. This is also a method of treating a mycotic aneurysm or infected thoracic aortic graft.

Ischemic spinal cord injury after cross-clamping of the descending aorta can occur independently of aortic disease. In a previous study we had shown a precipitous uniform fall of spinal surface oxygen tension downstream to the clamping site irrespective of level. In the present paper, the hemodynamic changes in the spinal and aortic collateral circulation were investigated. Pressures were measured in the proximal, distal, and excluded aortic segments (descending thoracic and lumbar aorta) as well as in the intercostal and the lumbar arterial beds. Before high aortic occlusion, pressures in the intercostal and lumbar arterial beds were lower than aortic pressure. Along with the postclamping fall in distal arterial pressure, intercostal and lumbar arterial bed pressure decreased further but remained above aortic pressure. Exclusion of the thoracic aorta by double clamping restored intercostal bed pressure almost to control, whereas exclusion of the abdominal aorta hardly affected lumbar bed pressure. We conclude that spinal collateral circulation is more highly developed in the thoracic than in the lumbar region. After aortic cross-clamping, blood tends to drain away from the spinal cord rather than supplying it longitudinally. Under clinical conditions, therefore, retrograde bleeding into the opened aorta as well as into the aorta downstream to the distal clamp should be minimized and larger vessels originating from the aorta should promptly be anastomosed to the graft.

Various anesthetic and surgical techniques have been recommended with or without cerebral function monitoring in attempts to reduce the risk of carotid endarterectomy, but there is no consensus as to the ideal method for performing this procedure. General anesthesia is now the most common anesthetic technique used, but of 337 carotid endarterectomies performed by the author's service from 1981 through 1985, 305 (91%) were conducted with regional anesthesia. This paper presents the morbidity and mortality rates for those patients. There were two perioperative transient ischemic attacks (0.66%), two perioperative strokes (0.66%), and two perioperative deaths (0.66%). No patient in the series suffered a myocardial infarction within 30 days after endarterectomy. This series demonstrates that carotid endarterectomy can be performed with good results using regional anesthesia, which facilitates intraoperative cerebral function monitoring. Regional anesthesia is associated with a very low incidence of postoperative hypertension and perioperative myocardial infarction.

Acute early postoperative femoral-distal bypass graft failure associated with profound lower extremity ischemia is unusual because early graft failure commonly reverts leg circulation to the preoperative status. Two cases are reported where the etiology of profound early postoperative ischemia and graft failure were not due to technical aspects of graft reconstruction itself but rather to vascular clamp injury to a severely atherosclerotic common femoral artery with early postoperative common femoral artery, profunda femoris artery and graft thrombosis. This event requires immediate recognition and common femoral artery reconstruction for limb salvage.

A prospective series of carotid endarterectomies were performed with patients given local anesthesia in an attempt to determine the efficacy of intraoperative EEG monitoring and/or stump pressure measurements in predicting the need for carotid shunting. Carotid artery stump pressure was measured and EEG changes noted; however, neither low stump pressure nor EEG changes influenced the decision for shunt insertion. A shunt was only used if a neurologic deficit developed during carotid clamping. A total of 134 carotid endarterectomies were done in 121 patients. Sixty-six patients were men and 55 were women with ages ranging from 41 to 88 years. Indications included transient ischemic attacks in 57 (43%), prior stroke in 25 (19%), vertebrobasilar symptoms in nine (6%), and asymptomatic patients with high-grade stenosis, 43 (32%). Thirteen patients (9.7%) developed neurologic deficits following carotid clamping and had shunts inserted. All deficits cleared following shunt insertion. Nine of the 13 had EEG changes, but in four, EEGs were unchanged despite the occurrence of clear-cut neurologic changes. Stump pressure in the 13 patients ranged from 14 to 78 mm Hg. Ten were greater than 24 mm Hg and three were more than 50 mm Hg. In 121 operations no neurologic deficits occurred during carotid clamping and no shunts were inserted. In 13 of these operations, significant EEG changes were noted. Stump pressures in these 13 with EEG changes ranged from 15 to 120 mm Hg. In seven, stump pressure was greater than 50 mm Hg. There were no deaths in the series. Two (1.5%) temporary and one (0.7%) permanent postoperative deficits occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Bands around extremities may be from congenital, infectious, accidental, or purposeful causes. The older child may reveal the cause of self-inflicted or caregiver-inflicted banding. Banding in a nonverbal child will challenge the diagnostic acumen of the physician. Bands of unknown cause, or bands that may have been placed purposefully by a caretaker, must be reported as possible child abuse. Failure of the caretaker to seek help for the consequences of a band may suggest that the bands were intentionally placed. This failure may also be construed as medical neglect. Four cases of banding, which were referred to a child abuse program for consultation, are described.

A lethal gastric perforation occurred after a gastric banding procedure, which was complicated with splenectomy. Prompted by this incident, an experimental study was undertaken in which regional blood flow in the stomach was measured in anesthetized cats after gastric banding or splenectomy or both. A fatal course with an extensive ischemic lesion of the stomach near the banding area was seen in all the cats with the combined procedure after 5 to 12 days. Banding alone reduced gastric blood flow within 24 hours, particularly on the greater curvature. Splenectomy also reduced blood flow along the greater curvature within 2 weeks. The combined procedure showed similar flow changes within 24 hours. The implication of these experimental results is that, if the spleen must be removed, the performance of gastric partitioning for morbid obesity should be reconsidered.

Iatrogenic vascular injury may occur during peripheral revascularization procedures secondary to the application of vascular occlusive devices. This review summarizes the known mechanical causes of such injury, relates this to clamp design, and suggests methods to minimize such injury by appropriate selection and handling of vascular occlusive clamps.

Seventeen patients undergoing elective repair of abdominal aortic aneurysm were examined to determine the causal mechanism for postoperative hypertension. In nine patients who had elevated systemic pressure after surgery, there were no correlations between mean arterial pressure and values of peripheral renin activity or angiotensin II. Further, no relation was demonstrated between systemic pressure and the volumes of crystalloid, colloid infused or milliequivalents of sodium administered pre- and intraoperatively. Postoperative arterial pressure correlated best with the preoperative value.

Liver resection is performed in 15 pigs by means of low divergent Nd YAG laser, the hepatic pedicle being clamped and not. Clamping does not modify the efficiency of laser hemostasis during resection but increases the thickness of the ischemic layer underlying the cut liver edge. The coagulation necrosis and the edematous layer are more thickened. Migration of inflammatory cells and young fibrosis present at day 3 are gaining ground until day 15. During the same period, biliary neoductules and nodules of hepatic regeneration appear. Hepatic inflow being conserved, these reactions are delayed and less intensive. The hyperthermia, the inflammatory cellular reaction and the deepness of parenchymal damages induces by pedicle clamping are suitable for antitumoral surgery. Cooling effects of hepatic inflow are better for traumatic surgery.

A patient is reported in whom intraoperative somatosensory evoked potential (SEP) changes occurred in response to temporary clipping of the right middle cerebral artery. A period of 10 minutes elapsed before changes in SEP's in response to contralateral nerve stimulation were noted and, during the following 2 minutes, the waves decreased in amplitude and then were unrecordable. Waves of SEP, with amplitude similar to those recorded before clipping but with abnormal latency, returned within 45 seconds of removal of the clip, and the latency abnormalities persisted until the end of the operation. The patient awakened promptly at the end of the procedure with a dense left hemiparesis which resolved over 24 hours. At the end of 24 hours, the SEP's in response to median nerve stimulation were symmetrical in both latency and amplitude. This report demonstrates the accuracy of intraoperative evoked potential monitoring in demonstrating alterations of cerebral perfusion during aneurysm surgery. It also suggests that a prolonged period of observation may be necessary to assess the effects of temporary vessel occlusion during surgery on aneurysms or arteriovenous malformations.

The authors present a retrospective analysis of the management of deep vein thrombosis (DVT) and pulmonary embolism (PE) in neurosurgical patients at the Massachusetts General Hospital from January, 1978, through June, 1982. There were 44 cases of DVT and 13 cases of PE. Management modalities included observation only, femoral vein ligation, inferior vena cava clipping, transvenous placement of an inferior vena cava filter or umbrella, and anticoagulation therapy. Six (75%) of eight patients with symptomatic DVT who were managed by observation alone had subsequent pulmonary emboli, and three (38%) died. Femoral vein ligation was followed by PE in one of four cases and led to significant leg swelling in two others. Neither observation alone nor femoral vein ligation can be recommended as routine management options. Partial inferior vena cava interruption with a De Weese clip, Kim-Ray Greenfield filter, or Mobin-Uddin umbrella all successfully prevented pulmonary emboli. The major problem associated with these methods was leg edema, which occurred in 47% of patients with clip placement, 25% with filter placement, and 21% with a Mobin-Uddin umbrella. Anticoagulation therapy was associated with a complication rate of 29% and a mortality rate of 15%. Fatal PE and paradoxical hypercoagulability with gangrene of a lower extremity were the causes of death. In one patient, hemorrhage into a glioblastoma occurred following discontinuation of anticoagulation therapy when the coagulation parameters were normal. The authors conclude that: 1) management with observation alone of patients with symptomatic DVT places the patient at risk for the development of life-threatening pulmonary emboli; 2) the safety and timing of therapeutic anticoagulation in postoperative neurosurgical patients or patients with tumors is unclear; and 3) partial interruption of the inferior vena cava with a transvenous filter successfully prevents PE and may represent a safer alternative to anticoagulation therapy.

Hemodynamic data of 8 patients undergoing planned resection of abdominal aortic aneurysm are statistically analyzed by variance analysis ("patient" factor and "time" factor). The results are: 1. "Patient" factor exists for all the variables studied. 2. "Time" factor is present for some of them. After aortic clamping, there is a significant decrease of the systolic index (p less than 0.05) and of the left ventricular systolic work index (p less than 0.01). After aorting declamping, a high significant increase of the mean right auricular pressure (p less than 0.001) and of mean capillary wedge pressure (p less than 0.001) are seen. Similar results are observed at the end of surgery. The results are commented with regard of the literature.

We address the question of whether an oxygen debt develops during a period of abdominal aortic cross-clamping that may explain observed hemodynamic changes. Group 1 received morphine sulfate (1 mg/kg) during induction of anesthesia. Group 2 received same dose of morphine sulfate. Group 3 received 4 mg/kg of morphine sulfate. We measured the oxygen consumption (VO2) and the carbon dioxide production levels (VCO2), as well as hemodynamic and biochemical parameters. In groups 1 and 3, VO2 and VCO2 decreased 10% to 13% following abdominal aortic cross-clamping compared with values measured before cross-clamping. In group 2, VO2 and VCO2 decreased 3% and 7%, respectively. On unclamping, the greatest increase in VO2 was observed in group 3 (26%), while in groups 1 and 2, VO2 rose 18% and 5%, respectively. In all three groups, metabolic changes were not paralleled by hemodynamic or temperature changes. Results indicate that oxygen debt developed during abdominal aortic cross-clamping, but this has no effect on hemodynamic changes seen after unclamping. Higher dosage of narcotic administered during anesthetic induction did not temper increase in metabolic rate observed after unclamping.

Clamping and declamping during aortic surgery produce a hemodynamically significant myocardial stress. The cardiovascular (CV) response to this stress may be adversely altered by calcium antagonists and beta-adrenoreceptor blockade employed to control symptomatic coronary artery disease. This study evaluated the effect of verapamil (V), propranolol (P), and their combination (P + V) on the CV response to infrarenal abdominal aortic cross-clamping and declamping in anesthetized dogs. Six dogs received P as a bolus of 0.5 mg/kg 20 min before clamping. Six additional dogs received V as a 300 micrograms/kg bolus followed by a V infusion of 6 micrograms/kg/min for 20 min before clamping. A third group of six dogs received the P bolus followed 20 min later by the V regimen (P + V). In both the V and P + V groups, 6 micrograms/kg/min V was infused throughout the clamping and declamping sequence. A fourth group of six control dogs received no cardioactive drugs during the experiment. Heart rate, mean aortic blood pressure, left ventricular end-diastolic pressures, peak rate of rise of left ventricular pressure, cardiac output, and systemic vascular resistance were measured in all animals before aortic cross-clamping, at 5 and 40 min after clamping, and 5 min after declamping. The results demonstrated additive negative chronotropic and inotropic properties of P + V therapy with a more significantly adverse effect than that of either drug alone. The implications of this study warrant added caution when patients treated with these drugs undergo abdominal aortic surgery.

The development of vascular clamps requires a reliable method to quantitate clamp-related vascular injuries. The degree of vessel damage usually is estimated subjectively from photomicrographs made with scanning electron microscopy. In order to test whether the use of vascular rings to assess residual vascular function may be a better method, rabbit thoracic aortas were occluded by five types of clamps: a Fogarty softjaw bulldog, a Fogarty Hydragrip, a 6-inch Satinsky clamp, an Edslab bulldog, and a silicone vessel band. Each area of clamp injury was sectioned into a vascular ring and suspended in a tissue bath. Residual vascular function was determined by contraction in response to phenylephrine and by relaxation in response to methacholine chloride and sodium nitroprusside. Morphologic studies with use of Evans blue dye and scanning electron microscopy complemented the vascular-function studies. The Fogarty bulldog clamp was the best at preserving vascular contraction and relaxation; the more crushing Satinsky clamp was the worst. The testing of vascular rings for residual function appears to be a useful technique for objectively quantitating vascular clamp-related vascular damage.

Carotid endarterectomy has the potential to improve on the natural history of untreated carotid artery disease with respect to subsequent infarction in symptomatic patients with causative angiographic lesions. This benefit of a reduced risk of stroke can be realized only if the perioperative morbidity and mortality rates are kept low. An approach to symptomatic carotid artery bifurcation disease is outlined, with a defined protocol of microsurgical endarterectomy utilizing barbiturate protection during the period of potential focal temporary cerebral ischemia. This protocol includes preoperative antiplatelet therapy, barbiturate anesthesia, the avoidance of an internal shunt, the use of the operating microscope, and strict control of postoperative hypertension. A series of 200 consecutive endarterectomies performed within this protocol in 180 patients and the resultant combined permanent morbidity and mortality rate of 1.5% are reported.

Three infants with coarctation of the thoracic aorta, patent ductus arteriosus (PDA), and ventricular septal defect (VSD) underwent repair of the coarctation in three different institutions. Despite a technically uncomplicated operation, each was noted to have significant paraplegia postoperatively. Retrospective analysis revealed that each patient had been hyperthermic during the time of aortic cross-clamping. It is possible that the hyperthermia, either alone or in combination with other factors, contributed to the development of paraplegia in these three infants.

To determine if intraoperative monitoring of somatosensory evoked potentials detects spinal cord ischemia, we subjected 21 dogs to aortic cross-clamping distal to the left subclavian artery. Group I animals (short-term studies, n = 6) demonstrated decay and loss of somatosensory evoked potentials at 8.5 +/- 1.1 minutes after aortic cross-clamping. During loss of somatosensory evoked potentials, significant decreases in spinal cord blood flow occurred in cord segments below T6. Significant reactive hyperemia occurred without normalization of somatosensory evoked potentials after reperfusion. Fifteen Group II animals (long-term studies) were studied to determine the relationship between duration of spinal cord ischemia (evoked potential loss) and subsequent incidence of paraplegia. Extension of aortic cross-clamping for 5 minutes after loss of somatosensory evoked potentials in six dogs resulted in no paraplegia (mean cross-clamp time 12.7 +/- 0.6 minutes). Prolongation of aortic cross-clamping for 10 minutes after evoked potential loss in nine dogs (mean cross-clamp time 17.6 +/- 0.6 minutes) resulted in a 67% (6/9) incidence of paraplegia 7 days postoperatively (p = 0.02 versus 10 minutes of aortic cross-clamping). These findings demonstrate that simple aortic cross-clamping uniformly results in spinal cord ischemia and that such ischemia is detectable by monitoring of somatosensory evoked potentials. Duration of ischemia, as measured by the time of evoked potential loss during the cross-clamp interval, is related to the incidence of postoperative neurologic injury.

No significant changes were found in heart rate, blood pressure, cardiac output, arterial blood gases or physiological deadspace: tidal volume ratio before and after clamping and unclamping the abdominal aorta below the renal vessels. Nevertheless, drugs should be available to reduct the afterload on the heart if any evidence of myocardial ischaemia appears during the period of aortic clamping. The importance of maintaining an adequate circulating blood volume at all times is stressed.

Twelve cases of probable embolic complication occurring during or after therapeutic occlusion of the internal carotid artery are summarized briefly. In each case, an extracranial-to-intracranial bypass procedure had been performed. These cases were collected from an informal survey of 30 neurosurgeons. In most instances, the middle cerebral artery became occluded as a result of an embolus, probably formed in the occluded internal carotid artery or possibly in the giant aneurysm being treated. The literature on surgical carotid occlusion is reviewed, with particular emphasis on the frequency and pathogenesis of ischemic complications.

The effectiveness and complications of gastric banding were evaluated in 15 miniature pigs. A Gore-tex or Dacron graft was employed to encircle the stomach. The animals were divided into five groups, three pigs in each group. Group 1 had a 13 mm pouch stoma with a Gore-tex band, Group 2 had a 16 mm pouch stoma with a Gore-tex band, Group 3 had a 13 mm pouch stoma with a Dacron band, Group 4 had a 16 mm pouch stoma with a Dacron band, and Group 5 had a sham operation. The weight variation in the control group was significantly higher than that in the other groups at the ninth postoperative week (p less than 0.05). There was no significant difference among Groups 1, 2, 3, and 4. The gastric band had migrated distally in seven pigs. It was located in the body of the stomach in four animals and in the pylorus in three. These three pigs died from stenosis of the pylorus. The band had eroded and penetrated all stomach layers in three other animals. There was no difference in the incidence of postoperative complications between the Gore-tex and Dacron band groups. The use of this simple operation in the treatment of the morbidly obese patient should be applied with caution.

In a consecutive series of 25 coronary bypass operations, the postoperative serum activity levels of total creatine kinase (CK) and its more heart-specific isoenzyme CK-MB were examined and related to the levels of aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT) and thermostable lactate dehydrogenase (LD-T), to electrocardiographic (ECG) findings and to surgical characteristics. Detectable CK-MB activity was found in all patients, usually appearing while the operation was still in progress. Peak CK-MB occurred earlier than peak total CK. There was no ECG evidence of myocardial infarction in any patient. The degree of postoperative CK-MB elevation, however, correlated to the duration of extracorporeal circulation (ECC) and aortic cross-clamping (AC). After 120 min of ECC and 70 min of AC, release of CK-MB, as well as of the other enzymes studied, increased considerably. There was a significant correlation between high CK-MB activity and high early postoperative activities of total CK, ASAT and LD-T. When CK-MB determinations are not available, ASAT is preferable to total CK or LD-T in the early evaluation of operative myocardial injury. From the fourth postoperative day, only LD-T is informative in this respect; a second rise of ASAT and ALAT is probably of hepatic origin.

Incidental prophylactic inferior vena cava clipping (IVCC) has been used in 30 patients undergoing colonic operations. The results obtained compare quite favorably with other methods of preventing postoperative pulmonary embolism (PE). This procedure would be justified in patients with a postoperative PE risk greater than 5 to 10 per cent. Practical criteria to identify this group of patients are presented, and the value of utilizing a risk profile is emphasized. There is no mortality from the procedure itself, and the morbidity was limited to lower-extremity edema in three patients who otherwise could have been expected to develop PE. The edema lasted two months in one patient and cleared rapidly in the other two. Attesting to the procedure's effectiveness, there were no cases of recurrent PE. Caval partition is an appealing mode of prophylaxis in high-risk patients because of its safety, efficacy, and permanence.