[What should no longer be seen when performing a CPB]. / Ce qu'il ne faudrait plus voir dans la conduite de la CEC.

Cardiac surgery and cardiopulmonary bypass (CPB) have made significant progress in recent years. Despite these efforts, adverse events continue to occur during surgery. From recent studies of incidents and accidents during CPB, this article focuses on critical recommendations to respect when in charge of a CPB. Some facts are based only on data unsupported by scientific research. Others have not proven their benefit in terms of postoperative morbidity or mortality. The management of anticoagulation, hematocrit, pump flow, and the temperature is discussed. Finally, the importance of teamwork especially in terms of cohesion and communication is highlighted.

Oxyhemoglobin induces caspase-mediated cell death in cerebral endothelial cells.

Damaged endothelium is one of the pathological changes of the cerebral vasospastic vessels following subarachnoid hemorrhage. Our recent study shows that oxyhemoglobin (OxyHb) induces apoptosis in vascular endothelial cells. Apoptosis generally requires the action of various classes of proteases, including a family of cysteine proteases, known collectively as the caspases. This study was undertaken to investigate the activation of caspases and the efficacy of caspase inhibitors, z-IETD-fmk and z-LEHD-fmk, for oxyhemoglobin-induced apoptosis in vascular endothelial cells. Cultured bovine brain microvascular endothelial cells (passages 5-9) were used for this study. OxyHb (10 micromol/L) was added during the 24-72 h incubation with and without caspase-8 or - 9 inhibitors (z-IETD-fmk and z-LEHD-fmk). Counting surviving cells, DNA laddering, western blotting of poly(ADP-ribose) polymerase, and measurement of caspase activities were employed to confirm the cytotoxic effects of OxyHb and the protective effects of the caspase inhibitors. OxyHb produced cell detachment in a time-dependent manner and increased caspase-8 and -9 activities in the cells. z-IETD-fmk and z-LEHD-fmk (100 micromol/L) attenuated OxyHb-induced cell loss, DNA laddering, and proteolytic cleavage of PARP, although a lower concentration (10 micromol/L) of caspase inhibitors showed partial effects. OxyHb activates caspase-8 and -9 in cultured vascular endothelial cells, and blocking the action of the caspases with the inhibitors efficiently prevents loss of vascular endothelial cells from OxyHb-induced apoptosis in vitro. These results suggest that the caspase cascade participates in OxyHb-induced apoptosis.

Endoscopic treatment of symptomatic septum pellucidum cysts: with some preliminary observations on the ultrastructure of the cyst wall: two technical case reports.

OBJECTIVE AND IMPORTANCE: We describe two patients with symptomatic septum pellucidum cysts managed by endoscopic fenestration. In each case, tissue from the cyst wall was studied to define the origin of the cyst wall and fluid. CLINICAL PRESENTATION: The patients, a 6-year-old boy and a 42-year-old man, each presented with headaches and a syncopal episode. Imaging studies demonstrated large septum pellucidum cysts with obstruction of the foramina of Monro. INTERVENTION: The patients underwent endoscopic transventricular cyst fenestration with a 4-mm steerable fiberscope. The fenestrations were created to allow communication with the right and left lateral ventricles. In one patient, adhesions between the cyst wall and the foramen of Monro were lysed with endoscopic monopolar cautery. Tissue from the cyst walls was removed for examination by electron microscopy. Postoperatively, the headaches and syncopal episodes resolved in both patients. CONCLUSION: Endoscopic fenestration of symptomatic septum pellucidum cysts produces immediate relief of the mass effect of the cyst and resolution of associated symptoms. Cannulation of the lateral ventricle before cyst fenestration prevents inadvertent injury to the fornices, thalamus, internal capsule, caudate nucleus, and septal and thalamostriate veins. The endoscopic approach allows the surgeon to ensure communication within the ventricular system, thus avoiding placement of a shunt. Preliminary ultrastructural analysis indicates that the cyst walls derive from the septum pellucidum rather than the choroid plexus or arachnoid. The cellular machinery necessary for fluid secretion was identified in some specimens.

Interventional magnetic resonance imaging guided aspiration and biopsy of a cystic midbrain tumor.

Interventional magnetic resonance imaging defines the intraoperative application of magnetic resonance imaging technology, permitting the surgeon to work in an open magnetic field. The application of this technology to pediatric neurosurgery allows precise intraoperative localization of pathology, real-time assessment of the anatomical consequences of surgical and anesthetic interventions, accountability of brain shifts, confirmation of the exact site of biopsy or completeness of lesion removal, and immediate identification of some intraoperative and early postoperative complications. We present the case of a young boy with a cystic left midbrain tumor who underwent interventional magnetic resonance imaging guided aspiration and biopsy to illustrate the surgical advantages of this technology.

Spontaneous dural sinus thrombosis in children.

The clinical course of spontaneous dural sinus thrombosis in children varies from indolent to fulminant. Although many different etiologies for the development of dural sinus thrombosis have been described, a full recovery can be anticipated in most children following rehydration and the administration of systemic antibiotics. Steroids, systemic anticoagulation and intrasinus thrombolysis may be beneficial in selected patients, although the efficacy of these therapies has not been established prospectively in children. We reviewed 12 pediatric patients with spontaneous dural sinus thrombosis (1978-1998) to determine the etiology, clinical course and best treatment options. In the absence of a hypercoagulable state, pediatric patients generally recover well with rehydration and antibiotics and do not require anticoagulation.

Anatomy of the shaken baby syndrome.

Shaken baby syndrome refers to the constellation of nonaccidental injuries occurring in infants and young children as a consequence of violent shaking. The typical victim of shaken baby syndrome is a male infant younger than six months of age who is alone with the perpetrator at the time of injury. Occurrence of the syndrome is unrelated to race, gender, socioeconomic status, or education. The characteristic injuries observed in shaken baby syndrome include subdural hemorrhages, retinal hemorrhages, and fractures of the ribs or long bones. Although each of these injuries may result from violent shaking of the victim, the most severe brain injuries result from the addition of a forceful impact of the infant's or child's head against a firm surface. The unique anatomic features of the infant's head and skeletal system, which account for the type and pattern of injuries observed in shaken baby syndrome, are emphasized in this article.

Expanding cyst of the septum pellucidum. Case report.

Expanding cysts of the septum pellucidum, although rare, may be a cause of significant neurological dysfunction. Most become symptomatic as a result of obstruction of the interventricular foramina and produce headaches, papilledema, emesis, and loss of consciousness. Behavioral, autonomic, and sensorimotor symptoms occur when an expanding cyst impinges on the structures of the hypothalamoseptal triangle or impairs the deep cerebral venous drainage. Neuroophthalmological symptoms may develop as a consequence of hydrocephalus or direct compression of visual structures. The authors describe the case of a young boy with an expanding septum pellucidum cyst who presented with a sudden, severe headache and loss of consciousness. In addition, he had a history of hyperactivity and progressively declining school performance. All symptoms resolved following decompression of the cyst. Seventeen cases from the literature are reviewed. The pathophysiological mechanisms underlying the development of symptoms secondary to expanding septum pellucidum cysts are outlined, and the related clinical neuroanatomy is described. A model is proposed for the natural history of expanding septum pellucidum cysts that provides a rational basis for understanding their clinical behavior and response to intervention. In most cases, fenestration or shunting will relieve the obstructive hydrocephalus and mass effect caused by the cyst and will produce rapid symptomatic improvement.

Inhaled cigarette smoke selectively reverses human hypoxic vasoconstriction.

The acute effects of the inhaled gas phase of cigarette smoke on pulmonary (PAP) and systemic (SAP) arterial pressures and on plasma arterial cGMP content were compared with those of inhaling 10, 20 and 80 ppm nitric oxide (NO) in one healthy adult volunteer spontaneously breathing a hypoxic gas mixture. Hypoxia (FIO2 0.12) induced a sustained, stable pulmonary vasoconstriction. Inhaled NO induced a dose-dependent fall in PAP; plasma cGMP rose from 39.4 (hypoxia) to 164 pmol/ml (hypoxia plus 80 ppm NO). Exposure to cigarette smoke induced a rapid, consistent and reversible fall in PAP; plasma cGMP rose from 45.5 (hypoxia) to 138 pmol/ml (hypoxia plus cigarette smoke). Neither NO nor cigarette smoke inhalation induced any change in SAP. These data suggest that exposure to cigarette smoke is able selectively to reverse acute hypoxic vasoconstriction in humans without causing systemic vasodilation, an effect likely mediated through the NO-cGMP pathway.

Effects of atrial pacing on right ventricular contractility after coronary artery surgery.

Increasing heart rate enhances the strength of contraction of cardiac fibers. This has been demonstrated in vitro and recently for the left ventricle. To study this phenomenon on the right ventricle, the effects of increasing heart rate by atrial pacing on right ventricular (RV) contractility were observed after coronary artery surgery in 20 patients. Right ventricular ejection fraction (EF) and stroke volume (SV) were measured by use of a rapid-response thermistor pulmonary artery catheter. Right ventricular volumes were calculated from EF and SV. Right ventricular contractility was assessed by the slope of the end-systolic pressure-volume relationship (ESPVR) before and after increasing RV preload by means of military antishock trousers (MAST) inflation. The dP/dtmax/end-diastolic volume index (EDVI) ratio, which is independent of ventricular preload, was also used as an inotropic index. Results are expressed as mean +/- SEM. Right ventricular preload, as reflected by RVEDVI, was increased by MAST inflation (99 +/- 6 mL/m2 v 106 +/- 7 mL/m2, P < 0.01), but returned to control values when inflation of MAST was combined with pacing (100 +/- 6 mL/m2). The slope of the RV ESPVR significantly increased when heart rate was increased (0.22 +/- 0.03 mmHg/mL/m2 before pacing v 0.77 +/- 0.07 mmHg/mL/m2 during pacing, P < 0.05). The dP/dtmax/EDVI ratio was also increased by pacing (2.32 +/- 0.4 mmHg/min/mL/m2 before pacing v 3.15 +/- 0.5 mmHg/min/mL/m2 during pacing, P < 0.01). Moreover, cardiac index was increased by pacing alone (2.45 +/- 0.2 L/min/m2 v 2.78 +/- 0.2 L/min/m2, P < 0.01), and significantly more when MAST were inflated (2.94 +/- 0.2 mL/m2, P < 0.05 v pacing alone). It is concluded that increasing heart rate by atrial pacing increases RV inotropic status after coronary artery surgery.

[Do halogenated anesthetics protect from ischemic and reperfusion myocardial injuries?]. / Les anesthésiques halogénés protègent-ils contre les lésions myocardiques d'ischémie et de reperfusion?

Ischaemia and reperfusion of the myocardium are associated with cellular injuries leading to a decrease of contractile function and the occurrence of arrhythmias. As reperfusion of an ischaemic heart results in an intracellular overload of calcium, a calcium blocking agent pretreatment has been shown to exert a protective effect. By altering myocardial calcium fluxes, volatile anesthetics might also protect the myocardium from ischaemic damage and reperfusion injuries. A beneficial effect of volatile anesthetics on the ischaemic myocardium has been shown in numerous studies. These agents decrease the severity of ischaemia as well as the incidence of reperfusion arrhythmias and improve recovery of myocardial mechanics during reperfusion. They also preserve myocardial energetics and protect from oxygen-derived free radicals injury. However, some studies do not support these protective effects. The wide discrepancy between the various protocols might explain the discrepancy of the results. Enflurane and halothane seem to be more efficient than isoflurane. This cannot only be explained by different cardiovascular effects, but also by a specific effect on myocardial cells. Halothane and enflurane mainly decrease intracellular calcium availability by a direct effect on sarcoplasmic reticulum, while isoflurane only decreases the transsarcolemnal calcium entry. Enflurane and halothane have more beneficial effects than isoflurane on free radicals induced myocardial injuries. In conclusion, despite a wide diversity between the different studies, halothane and enflurane have better protective properties against ischaemia and reperfusion myocardial injuries than isoflurane.

[Post-traumatic aortic valve insufficiencies]. / Les insuffisances aortiques post-traumatiques.

Aortic regurgitation due to closed chest trauma is rare. It is related either to a valve lesion itself (ruptured cusp) or to trauma of the ascending aorta (subadventitial rupture with prolapse of the underlying aortic valve cusp). Four cases are described, 2 men and 2 women aged 30 to 66 years, after severe injuries in road traffic accidents: three patients had rupture of the aorta and the other had isolated rupture of the non-coronary aortic valve cusp. This pathology is unique due to the pathogenic mechanism associated with multiple thoracic injuries (right costal flap, sternal fracture, pulmonary contusion ...). The polytraumatic context explains the diagnostic difficulties and the secondary importance of the valve problem. Late surgery of these lesions was conservative in 3 cases: valve replacement was necessary in 1 case. If the haemodynamic tolerance of the aortic regurgitation is good, surgery should be deferred until the polytraumatic emergency has been dealt with. Good surgical results, often with conservative procedures, encourage earl operation after the acute polytraumatic period.

[Preoperative evaluation of respiratory function in thoracic surgery. Do reliable predictive criteria exist in that type of surgery?]. / Evaluation fonctionnelle ventilatoire pré-opératoire en chirurgie thoracique. Existe-t-il des critères de prédiction fiables dans ce type de chirurgie?

A cautions analysis of the respiratory preoperative study may decrease morbidity and mortality after pulmonary surgery. To search for predictive criteria of respiratory complications following this kind of surgery, 454 patients have been studied retrospectively. Morbidity was defined as the need for postoperative ventilation. Preoperative criteria were divided in clinical (age, obesity, history of pulmonary disease, dyspnea, score of Karnofsky), laboratory (blood gases, spirometry) and surgical (kind of procedure). Three criteria were significant for morbidity (15 ventilated patients) and mortality (27 deaths): age (> 65 years), obesity, hypocapnia (pCO2 < 4.1 kPa-31 mmHg). Analysed spirometric values were no significant.

[Hemodynamic complications during the recovery period after anesthesia]. / Les complications hémodynamiques au cours de la phase du réveil de l'anesthésie.

In the postoperative period the alterations of blood pressure are the main hemodynamic complications. Hypotension or hypertension may compromise the coronary circulation and increase the metabolic demand of the myocardium. Pulmonary oedema is the most frequent manifestation of heart failure. The aim of its treatment is to increase myocardial contractility and decrease the metabolic demand. Myocardial ischemia is mostly silent and is an important correlate of adverse cardiac outcomes. The treatment of these hemodynamic events starts during the peroperative period by prevention of their risk factors.

[Value of biological tests in the early diagnosis of acute steatosis in pregnancy]. / Intérêt des examens biologiques pour le diagnostic précoce d'une stéatose hépatique aiguë gravidique.

Four cases of acute fatty liver of pregnancy occurring over a ten year period are reported. All four patients had a caesarean section and one died postoperatively. The seven children (three twin pregnancies) were all alive. The early clinical signs were unspecific. Jaundice was the only one occurring in all patients. Routine biological tests before the jaundice develops may be of help for a diagnosis early enough to start the treatment in patients with unspecific gastrointestinal or hepatic manifestations, especially the liver function and blood coagulation tests. These latter allow to discord the diagnosis of viral hepatitis and the "Haemolysis-Elevated Liver enzyme concentrations-Low Platelets" (HELLP syndrome) respectively. Indeed, only a liver biopsy can ascertain the diagnosis.

[Hemodynamic effects of milrinone in the treatment of cardiac insufficiency after heart surgery with extracorporeal circulation]. / Effets hémodynamiques de la milrinone dans le traitement de l'insuffisance cardique après chirurgie cardiaque sous circulation extracorporelle.

Milrinone is an inotropic agent of the phosphodiesterase inhibitor family. In common with all molecules of this class it has both positive inotropic and vasodilator effects. The haemodynamic effects of 3 dosages of milrinone were studied in 25 patients with low output states after open heart surgery. The low cardiac output was defined as a cardiac index of less than 2.5/min/m2 and pulmonary capillary pressures greater than 8 mmHg. Milrinone was administered as a bolus of 50 micrograms/kg/min over 10 minutes followed by a continuous infusion for at least 12 hours. Six patients were given 0.375 micrograms/kg/min, six patients 0.5 micrograms/kg/min, and 13 patients 0.75 g/kg/min. A significant increase in cardiac index was observed but without any difference between the 3 groups. The heart rate and stroke volumes were increased. There was a mild reduction in systemic blood pressure with a decrease in systemic arterial resistances which returned to almost normal values. Left and right filling pressures did not decrease significantly from the initial values until the end of the bolus injection. Indirect measurements of myocardial oxygen consumption showed an increase in this parameter. There were no changes in blood gas concentrations. The treatment was stopped in only one patient because of peripheral vasodilation. Two patients developed supraventricular tachycardia of no consequence. Milrinone may therefore be proposed as treatment of first intention of low cardiac output states after open heart surgery. It is associated with a mild vasodilatory effect. Improved myocardial function is observed providing attention is paid to vascular filling. None of the maintenance doses used after the bolus injection was shown to be more effective than the others.

Blood salvage in cardiac surgery.

The aim of this study was to evaluate blood salvage provided by an intraoperative blood recovery system (IBRS) and a mediastinal drainage blood recovery system (MBRS) during and after cardiac surgery. Sixty-six patients undergoing aortocoronary bypass surgery were randomly assigned to three groups of 22 patients each. In group I, patients received only homologous blood (HB). Group II and group III patients received the blood content of the oxygenator after concentration by an IBRS at the end of the operation. In group III, patients also received their own mediastinal drainage blood, shed for 6 hours after operation, after concentration and washing in a MBRS. The patients were transfused with homologous blood if needed, in order to obtain a hematocrit of 28% at the end of operation, 30% the following day, and a hemoglobin level over 10 g/dL while on the cardiac surgery ward (8 to 10 days). The three groups were comparable with respect to age, body surface, preoperative and postoperative hematocrits, number of grafts, bypass duration, and postoperative mediastinal blood loss. The amount of HB that was transfused during the operation was significantly lower in groups II and III than in group I (P less than 0.0001). After the operation it was significantly lower in group II than in group I (P less than 0.05), and in group III versus group I. Thus, 13.6% of patients in group II and 38% of patients in group III did not require HB transfusion. No infection, renal dysfunction, or coagulation disorders were observed. It is concluded that the use of an IBRS allows a significant saving of HB. However, because it does not avoid all HB requirements, it should be associated with other techniques to avoid blood transfusion such as the MBRS or predonation.

Cervical laminectomy and dentate ligament section for cervical spondylotic myelopathy.

Seventy-five patients who underwent surgical treatment for cervical spondylotic myelopathy were evaluated with respect to the operative procedure performed and their outcome. Forty patients underwent a laminectomy plus dentate ligament section (DLS), 18 underwent laminectomy alone, and 17 underwent an anterior cervical decompression and fusion (ACDF). The patients were evaluated postoperatively for both stability and for neurologic outcome using a modification of the Japanese Orthopaedic Association Assessment Scale. Functional improvement occurred in all but one patient in the laminectomy plus DLS group. The average improvement was 3.1 +/- 1.5 points in this group; whereas the average improvement in the laminectomy and the ACDF groups was 2.7 +/- 2.0 and 3.0 +/- 2.0 points respectively. All of the patients who improved substantially (greater than or equal to 6 points) in the laminectomy plus DLS and the laminectomy alone groups had normal cervical spine contours (lordosis). The remainder had either a normal lordosis or no curve (no kyphosis or lordosis). All patients in the ACDF group had either a straight spine or a cervical kyphosis. These factors implicate spine curvature, in addition to choice of operation, as factors which are important in outcome determination. No problems with instability occurred in either the laminectomy or the laminectomy plus DLS group. Two patients incurred problems with stability in the ACDF group. Both required reoperation. In addition, four patients in this group who initially improved, subsequently deteriorated. Six patients in the laminectomy plus DLS group had a several day febrile episode related to an aseptic meningitis process. Laminectomy plus DLS is a safe and efficacious alternative to laminectomy for the treatment of cervical spondylotic myelopathy. The data presented here suggests that myelopathic patients with a cervical kyphosis are best treated with an ACDF and that patients with a normal cervical lordosis are best treated with a posterior approach. Although some selected patients may benefit from DLS, no criteria are available which differentiate this small subset of patients.