Pirjo Manninen

Brain Tumor Surgery with the Toronto Open Magnetic Resonance Imaging System: Preliminary Results for 36 Patients and Analysis of Advantages, Disadvantages, and Future Prospects

OBJECTIVEnFrameless navigation systems represent a huge step forward in the surgical treatment of intracranial pathological conditions but lack the ability to provide real-time imaging feedback for assessment of postoperative results, such as catheter positions and the extent of tumor resections. An open magnetic resonance imaging system for intracranial surgery was developed in Toronto, by a multidisciplinary team, to provide real-time intraoperative imaging.nnnMETHODSnThe preliminary experience with a 0.2-T, vertical-gap, magnetic resonance imaging system for intraoperative imaging, which was developed at the University of Toronto for the surgical treatment of patients with intracranial lesions, is described. The system is known as the image-guided minimally invasive therapy unit.nnnRESULTSnBetween February 1998 and March 1999, 36 procedures were performed, including 21 tumor resections, 12 biopsies, 1 transsphenoidal endoscopic resection, and 2 catheter placements for Ommaya reservoirs. Three complications were observed. All biopsies were successful, and the surgical goals were achieved for all resections. Problems included restricted access resulting from the confines of the magnet and the imaging coil design, difficulties in working in an operating room that is less spacious and familiar, inconsistent image quality, and a lack of nonmagnetic tools that are as effective as standard neurosurgical tools. Advantages included real-time imaging to facilitate surgical planning, to confirm entry into lesions, and to assess the extent of resection and intraoperative and immediate postoperative imaging to confirm the extent of resections, catheter placement, and the absence of postoperative complications.nnnCONCLUSIONnIntraoperative magnetic resonance imaging has great potential as an aid for intracranial surgery, but a number of logistic problems require resolution.

Postoperative nausea and vomiting after craniotomy for tumor surgery: a comparison between awake craniotomy and general anesthesia

STUDY OBJECTIVEnTo assess the frequency of postoperative nausea and vomiting (PONV) in patients following an awake craniotomy compared to general anesthesia for tumor surgery.nnnDESIGNnProspective observational and chart review of all patients having a craniotomy for tumor during one year.nnnSETTINGnPostanesthesia care unit (PACU) and intensive care unit (ICU) of a university hospital.nnnPATIENTSn187 patients were reviewed. 107 patients who had a craniotomy for supratentorial tumor that was less than six hours in duration were analyzed and compared (50 awake craniotomy vs. 57 general anesthesia).nnnINTERVENTIONSnMedical records were reviewed for events after the first four hours until discharge. The occurrence and the time of any nausea, vomiting; the administration of antiemetics and analgesic drugs; and complications were documented.nnnMEASUREMENTSnFrequency of nausea, vomiting, administration of antiemetics and analgesia, and outcome between the two groups were compared using Chi-square and Students t-test.nnnMAIN RESULTSnThe frequency of nausea (4% vs. 23%; p = 0.012) and vomiting (0% vs. 11%; p = 0.052) were less in patients having an awake craniotomy compared to general anesthesia, but only during the first four hours. The administration of postoperative analgesia was not different between the two groups and did not influence the frequency of PONV.nnnCONCLUSIONnThe frequency of PONV during the initial recovery phase was less in patients having an awake craniotomy for tumor surgery than in patients having a similar procedure with general anesthesia.

Venous air embolism during awake craniotomy in a supine patient.

PurposeTo report a non-fatal case of intraoperative venous air embolism (VAE) during an awake craniotomy. VAE presented with unusual clinical features.Clinical featuresVAE during an awake craniotomy has not been reported frequently. The patient we describe presented with persistent coughing followed by tachypnea, hypoxia and reduction in end-tidal CO2 during dural opening while undergoing an awake craniotomy in the supine position. Cardiovascular variables were stable during the episode except for transient hypertension. Having ruled out airway obstruction and low cardiac output, we concluded that air embolism was the cause. The patient responded immediately to the standard treatment of air embolism and recovered without any complication.ConclusionThis case illustrates a VAE during an awake craniotomy and emphasizes the importance of early diagnosis in the management.RésuméObjectifPrésenter un cas non mortel d’aéroembolie veineuse peropératoire (AEV) survenue pendant une craniotomie vigile. L’AEV présentait des caractéristiques cliniques inhabituelles.Éléments cliniquesL’AEV qui survient pendant la craniotomie vigile n’a pas été souvent rapportée. Le patient que nous décrivons a présenté une toux persistante suivie de tachypnée, d’hypoxie et d’une baisse du CO2 télé-expiratoire pendant l’ouverture durale pour une craniotomie vigile en décubitus dorsal. Les variables hémodynamiques ont été stables pendant l’épisode, sauf pour l’hypertension transitoire. Nous avons d’abord écarté la possibilité d’une obstruction des voies aériennes et un faible débit cardiaque pour en arriver au diagnostic d’embolie gazeuse. Le patient a immédiatement réagi au traitement standard de l’embolie gazeuse et il s’est remis sans complication.ConclusionCe cas illustre un AEV pendant une craniotomie vigile et souligne l’importance d’un diagnostic précoce pour le traitement.

Canadian Cardiovascular Society/Canadian Anesthesiologists' Society/Canadian Heart Rhythm Society Joint Position Statement on the Perioperative Management of Patients With Implanted Pacemakers, Defibrillators, and Neurostimulating Devices

There are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients. The document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individuals type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference. The document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable.

Remifentanil with morphine transitional analgesia shortens neurological recovery compared to fentanyl for supratentorial craniotomy

PurposeTo compare the recovery profiles, efficacy and safety of remifentanil and morphine for transitional analgesia with fentanyl in patients undergoing elective craniotomy for supratentorial mass lesions.MethodsNinety-one patients were enrolled in this prospective, randomized, multicentre study. Anesthesia was induced with thiopental and remifentanil (1.0 μg · kg−1 bolus and a 1 μg · kg−1 · min−1 infusion) or fentanyl (1 μg · kg−1 bolus and a 1.0 μg · kg−1 · min−1 infusion). The opioid infusion continued until the level of anesthesia was deemed appropriate for intubation. Anesthesia was maintained with N2O/O2, isoflurane 0.5 MAC and remifentanil 0.2 μg · kg−1 · mirr−1 or fentanyl 0.04 μg · kg−1· min−1. At bone flap replacement, either morphine 0.08 mg · kg−1 (remifentanil group) or saline (fentanyl group) was given.ResultsSystolic blood pressure was greater in those receiving fentanyl during induction (145.6 ± 17.5 mmHgvs 128.8 ± 18.3 mmHg;P = 0.006) and intubation (126.9 ± 17.1vs 110.9 ± 16.5 mmHg;P < 0.001). Median time to tracheal extubation was similar but less variable in the remifentanil group (remifentanil = 8 min: range = 2–44 min; fentanyl = 8 min: range = 1–732 min). The fentanyl patients required a longer time to achieve the first normal neurological score (fentanyl = 38.0 min; remifentanil = 26.0 min;P = 0.035). Both the anesthesiologists and the recovery room nurses rated remifentanil better with respect to level of consciousness. Analgesics were required earlier in patients receiving remifentanil; median time 0.5vs 1.08 hr,P < 0.001.ConclusionsRemifentanil is a suitable alternative to fentanyl in supratentorial craniotomy. Time to preoperative neurological recovery is faster and morphine provides some transitional analgesia without compromising the quality of recovery.RésuméObjectifComparer les profils de récupération, l’efficacité et l’innocuité de l’analgésie transitionnelle avec rémifentanil et morphine, ou avec fentanyl, chez des patients devant subir une craniotomie réglée pour des masses intracrâniennes sus-tentorielles.MéthodeQuatre-vingt-onze patients ont participé à l’étude prospective, randomisée et multlcentrlque. L’anesthésle a été induite avec du thiopental et du rémifentanil (bolus de 1,0 μg · kg−1 et perfusion à 1 μg · kg−1 · min−1) ou du fentanyl (bolus de 1 μg · kg−1 et perfusion à 1,0 μg · kg−1 · min−1). La perfusion d’oploïde s’est poursuivie jusqu’à un niveau d’anesthésle jugé approprié pour l’intubation. L’anesthésle a été maintenue avec un mélange N2O/O2, 0,5 CAM d’isoflurane et 0,2 μg · kg−1 · min−1de rémifentanil ou 0,04 μg · kg−1 · min−1de fentanyl. Au moment de replacer le volet osseux, soit 0,08 mg · kg−1 de morphine (groupe rémifentanil), soit une solution saline (groupe fentanyl) a été administrée.RésultatsLa tension artérielle systollque a été plus élevée avec l’utilisation du fentanyl pendant l’Induction (145,6 ± 17,5 mmHg vs 128,8 ± 18,3 mmHg ; P = 0,006) et l’intubation (126,9 ± 17,1 vs 110,9 ± 16,5 mmHg ; P < 0,001). La durée moyenne de l’extubatlon endotrachéale a été similaire, mais moins variable avec le rémifentanil (rémifentanil = 8 min : étendue = 2–44 min ; fentanyl = 8 min : étendue = 1–732 min). Le premier score neurologique normal a été plus tardif avec le fentanyl (fentanyl = 38,0 min ; rémifentanil = 26,0 min ; P = 0,035). Les anesthéslologlstes et le personnel Infirmier de la salle de réveil ont mieux coté le rémlfentanll quant au niveau de conscience. Les analgésiques ont été demandés plus tôt par les patients recevant le rémlfentanll ; temps moyen de 0,5 vs 1,08 h, P< 0,001.ConclusionLe rémlfentanll remplace le fentanyl de façon appropriée pendant une cranlotomle sus-tentorielle. Le temps nécessaire à la récupération de la fonction neurologique préopératoire est plus court et la morphine fournit une analgésie transltlonnelle sans compromettre la qualité de la récupération.

Anesthesia for cerebral aneurysms: a comparison between interventional neuroradiology and surgery

Purpose: To review the anesthetic management of patients with cerebral aneurysms during treatment in the interventional neuroradiology (INR) suite compared with in the operating room.Methods: This was a retrospective chart review of 100 consecutive patients treated by endovascular coiling compared with 100 patients treated by surgical clipping of a cerebral aneurysm. Information compared and analyzed included demographics, preprocedure medical history, neurological status including location and size of aneurysm, anesthetic management, complications and patient outcome.P<0.05 was considered significant.Results: Patients in the INR group were older (54±15vs 49± 12 yr), had a greater incidence of pre-procedure cardiorespiratory problems (55vs 34 patients) and had more aneurysms located in the posterior fossa (68vs 11) (P<0.05). General anesthesia was used in all except seven INR patients who received conscious sedation. There were some differences in the anesthetic agents and techniques. There was less monitoring of INR patients; temperature (33vs 99 patients), intrarrterial catheter (22vs 100), central venous catheter (4vs 78), and evoked potential monitoring (0vs 100). There were no differences in the incidence of documented complications or in patient outcome.Conclusion: There were some differences in the anesthetic management of patients undergoing endovascular treatment of a cerebral aneurysm compared with treatment in the operating room. The patients in the INR suite were sicker and somewhat older and they received less invasive monitoring, but the complication rate and outcome did not differ.RésuméObjectif: Examiner la ligne de conduit adoptée pour l’anesthésie pendant le traitement d’anévrysmes cérébraux en neuroradiologie interventíonnelle (NRI) comparé au traitement en salle d’opération.Méthode: C’est une revue de dossíers rétrospectíve de 100 patíents successífs quí ont reçu une prothèse spíraíée, comparés à 100 patíents traítés par lígature chírugícale d’un anévrysme cérébral. Les ínformatíons comparées et analysées comprennent les données personnelles, l’histoíre médicale antérieure à l’interventíon, l’état neurologíque incluant le site et la taílle de l’anévrysme, la démarche anesthésique, les complications et l’évolution du patient. P<0,05 a été considéré comme signíficatifRésultats: Les patients du groupe de NRI étaient plus âgés (54±15 vs 49±12 ans). présentaient une plus forte incídence de problèmes cardiorespiratoíres antérieurs à l’opération (55 vs 34 patients) et avaient plus souvent des anévrysmes de la fosse postérieure (68 vs 11) (P<0,05). L’anesthésie générale a été utilisée chez tous, sauf chez sept patients de NRI quí ont reçu une sédation consciente. Différents agents et techniques anesthésiques ont été utilisés. Il y a eu moins de monítorage chez les patients de NRI; température (33 vs 99 patients), cathéter intra-artériel (22 vs 100), cathéter veineux central (4 vs 78), et potentiel évoqué (0 vs 100). L’incidence de complications notées ou l’évolution du patient n’ont pas présenté de différences.Conclusion: Certaines différences de gestion anesthésíque sont apparues quand on compare le traitement endovasculaíre d’un anévrysme cérébral au traitement en salle d’opération. Les patients de NRI étaient plus malades et plus âgés et ont reçu un monitorage moins effractif, ce quí n’a pas affecté le taux de complícations ní l’évolutíon de patients.

Craniotomy for suprasellar meningioma in a 28-week pregnant woman without fetal heart rate monitoring.

PurposeTo illustrate the anesthetic management of a craniotomy for suprasellar meningioma in a 28-week pregnant woman and to review the considerations for fetal monitoring during surgery.Clinical featuresA 33-yr-old woman presented at 28 weeks of gestation with rapidly deteriorating vision in her right eye. Neuroradiological investigations revealed a large suprasellar meningioma extending into the frontal lobe. She underwent a craniotomy for excision of the tumour at 28 weeks gestation because of the risk of irreversible blindness. Anesthetic management was tailored for pregnancy and an intracranial tumour. Intraoperative blood pressure was maintained within 10% of baseline and respiratory variables were stable. No fetal heart rate monitoring was used during the surgery, as there was no plan to perform an emergency Cesarean delivery even in the event of change in fetal monitoring. The aim was to treat the mother aggressively for any untoward events. She made a good neurological recovery after the procedure and had a spontaneous vaginal delivery at 40 weeks of gestation without any neonatal complications.ConclusionsAnesthetic management of a brain tumour during pregnancy should be tailored to the individual patient according to the circumstances. It is possible to perform this type of procedure without fetal heart rate monitoring. The decision regarding fetal monitoring should be based on the consensus of the multidisciplinary care team and the mother.RésuméObjectifIllustrer la composante anesthésique d’une craniotomie pour méningiome suprasellaire chez une femme enceinte de 28 semaines et revoir ce qui justifie l’usage du monitorage fœtal peropératoire.Éléments cliniquesUne femme de 33 ans a consulté à 28 semaines de grossesse pour une rapide détérioration de la vision à l’œil droit. Les examens neuroradiologiques ont révélé un important méningiome suprasellaire s’étendant dans le lobe frontal. Étant donné le risque de cécité irréversible, l’excision de la tumeur a été réalisée lors d’une craniotomie d’urgence. L’anesthésie a été planifiée en fonction de la grossesse et de la tumeur intracrânienne. La tension artérielle peropératoire a été maintenue dans les limites de 10% des conditions initiales et les variables respiratoires ont été stables. Le monitorage peropératoire de la fréquence cardiaque fœtale n’a pas été utilisé, car on n’avait pas planifié de césarienne d’urgence, même dans l’éventualité de changement au monitorage fœtal. L’objectif était un traitement rigoureux de la mère quoiqu’il arrive. La récupération neurologique a été bonne et suivie d’un accouchement par voie vaginale à 40 semaines, sans complications néonatales.ConclusionLe programme anesthésique de l’excision d’une tumeur cérébrale pendant la grossesse doit s’adapter à la patiente et aux circonstances. On peut réaliser ce type d’opération sans le monitorage fœtal. Mais c’est une décision qui doit être fondée sur un consensus de l’équipe multidisciplinaire de soignants et de la mère.

The history of awake craniotomy for brain tumor and its spread into Asia

In ancient times, awake craniotomy was used for trepanation to treat seizures and remove a variety of morbid conditions or even to permit the escape of evil air. In modern times, this technique was initially used for removal of epileptic foci with simultaneous application of brain mapping with electrical current. Further developments brought this technique into use for resection of tumors involving functional cortex. Recently, awake craniotomy has been described as an approach for removal of supratentorial tumors nonselectively, regardless of the involvement of eloquent cortex. It has been used in North America since the 1980s, then Europe, and recently has spread into Asia. Its spread to Asia could have significant impact based on the large population of patients and the low resource utilization associated with awake craniotomy.

Society position statement : Canadian Cardiovascular Society/Canadian Anesthesiologists' Society/Canadian Heart Rhythm Society joint position statement on the perioperative management of patients with implanted pacemakers, defibrillators, and neurostimulating devices.

PurposeThere are more than 200,000 Canadians living with permanent pacemakers or implantable defibrillators, many of whom will require surgery or invasive procedures each year. They face potential hazards when undergoing surgery; however, with appropriate planning and education of operating room personnel, adverse device-related outcomes should be rare. This joint position statement from the Canadian Cardiovascular Society (CCS) and the Canadian Anesthesiologists’ Society (CAS) has been developed as an accessible reference for physicians and surgeons, providing an overview of the key issues for the preoperative, intraoperative, and postoperative care of these patients.Principal findingsThe document summarizes the limited published literature in this field, but for most issues, relies heavily on the experience of the cardiologists and anesthesiologists who contributed to this work. This position statement outlines how to obtain information about an individual’s type of pacemaker or implantable defibrillator and its programming. It also stresses the importance of determining if a patient is highly pacemaker-dependent and proposes a simple approach for nonelective evaluation of dependency. Although the document provides a comprehensive list of the intraoperative issues facing these patients, there is a focus on electromagnetic interference resulting from electrocautery and practical guidance is given regarding the characteristics of surgery, electrocautery, pacemakers, and defibrillators which are most likely to lead to interference.ConclusionsThe document stresses the importance of preoperative consultation and planning to minimize complications. It reviews the relative merits of intraoperative magnet use vs reprogramming of devices and gives examples of situations where one or the other approach is preferable.RésuméObjectifPlus de 200xa0000xa0Canadiens vivent avec des stimulateurs cardiaques permanents ou des défibrillateurs implantables et plusieurs d’entre eux auront besoin d’une chirurgie ou de procédures effractives chaque année. Ils font face à des risques potentiels lorsqu’ils subissent une chirurgie. Cependant, par une planification et une formation appropriée du personnel de salle d’opération, les conséquences négatives liées aux dispositifs devraient être rares. Cet énoncé de position commune de la Société canadienne de cardiologie (SCC) et de la Société canadienne des anesthésiologistes (SCA) a été élaboré en tant que référence accessible aux médecins et aux chirurgiens, fournissant un aperçu des questions clés pour les soins préopératoires, peropératoires et postopératoires de ces patients.Constatations principalesLe document résume la littérature limitée de ce domaine, mais pour la plupart des questions, il repose largement sur l’expérience des cardiologues et des anesthésiologistes qui ont contribué à ce travail. Cet énoncé de position décrit comment obtenir des renseignements sur un stimulateur cardiaque adapté aux besoins individuels ou un défibrillateur implantable et sa programmation. Il souligne aussi l’importance de déterminer si un patient est grandement dépendant de son stimulateur cardiaque et propose une approche simple pour l’évaluation non élective de dépendance. Même si le document fournit une liste exhaustive des questions peropératoires auxquelles font face ces patients, l’accent est mis sur l’interférence électromagnétique résultant de l’électrocautère, et des conseils pratiques sont donnés en ce qui concerne les caractéristiques de la chirurgie, de l’électrocautère, des stimulateurs cardiaques et des défibrillateurs, lesquels sont les plus susceptibles de mener à une interférence.ConclusionsLe document souligne l’importance d’une consultation préopératoire et d’une planification pour minimiser les complications. Il revoit la pertinence relative à l’utilisation d’un aimant peropératoire par rapport à la reprogrammation des dispositifs et donne des exemples de situations où l’une ou l’autre des approches est préférable.

Posterior tibial nerve and median nerve somatosensory evoked potential monitoring during carotid endarterectomy

PurposeSomatosensory evoked potential (SSEP) monitoring using the median nerve (MN) modality during carotid endarterectomy is well established. This study assessed the usefulness of monitoring the posterior tibial nerve (PTN) SSEP as an adjunct to MNSSEP for detection of cerebral ischemia and as an indicator for the insertion of a shunt in patients undergoing a carotid endarterectomy.MethodsAll patients undergoing carotid endarterectomy during three years who had routine bilateral MNSSEP were also monitored with bilateral PTNSSEP. Patients received a shunt if there was a significant change (> 50% decrease in amplitude of cortical peak (N20) in the MNSSEP after cross clamping. The incidence, timing, and duration of all PTNSSEP changes were compared to MNSSEP changes.ResultsOne hundred fifty-three patients were studied. Significant changes in MNSSEP after cross clamp lead to insertion of a shunt in six patients. Changes in PTNSSEP occurred at almost the same time in three patients, four minutes before MNSSEP in one, three minutes later in one and no change in one patient. Good quality baseline tracings were obtained in 99% MNSSEP as compared to 88% PTNSSEP (P < 0.05). New postoperative neurological deficits occurred in four patients (2.6%), only one had significant evoked potential changes.ConclusionMonitoring of PTNSSEP is feasible and may be considered for an adjunct to MNSSEP or as an alternative modality if there are difficulties with MNSSEP. However, there may be a greater incidence of poor quality baseline tracings for PTNSSEP.RésuméObjectifLe monitorage du potentiel évoqué somato-sensitif (PESS) selon la modalité du nerf médian (NM) pendant l’endartériectomie de la carotide est bien connu. Nous voulions évaluer l’utilité du monitorage du PESS du nerf tibial postérieur (NTP) comme complément au PESSNM pour la détection d’ischémie cérébrale et comme indicateur pour l’insertion d’un shunt pendant une endartériectomie de la carotide.MéthodePendant trois ans, les patients devant subir une endartériectomie carotidienne et qui avaient un PESSNM de routine ont aussi eu un PESSNTP bilatéral. Ils ont reçu un shunt s’il y avait un changement significatif (> 50 % de diminution de l’amplitude du pic cortical (N20) du PESSNM après le clampage carotidien. L’incidence, l’ordre de déroulement et la durée des changements de PESSNTP et de PESSNM ont été comparés.RésultatsL’étude a porté sur 153 patients. Des changements significatifs de PESSNM survenus après le clampage croisé ont mené à l’insertion d’un shunt chez six patients. Des changements de PESSNTP sont survenus presque au même moment chez trois patients, quatre minutes avant le PESSNM chez un patient, trois minutes après chez un autre et aucun changement n’a été noté chez un troisième. Des tracés de base de bonne qualité ont été obtenus chez 99 % des PESS-NM comparés à 88% de PESSNTP (P < 0,05). De nouveaux déficits neurologiques postopératoires ont été observés chez quatre patients (2,6 %) dont un seulement présentait des changements significatifs de potentiel évoqué.ConclusionLe monitorage du PESSNTP est faisable et peut être considéré comme complément du PESSNM ou comme une modalité de remplacement devant des difficultés de PESSNM. Toutefois, il pourrait y avoir une plus forte incidence de tracés de base de pauvre qualité pour le PESSNTP.