Clinical indications for high-field 1.5 T intraoperative magnetic resonance imaging and neuro-navigation for neurosurgical procedures. Review of initial 100 cases.

Initial experiences are reviewed in an integrated operation theater equipped with an intraoperative high-field (1.5 T) magnetic resonance (MR) imager and neuro-navigation (BrainSUITE), to evaluate the indications and limitations. One hundred consecutive cases were treated, consisting of 38 gliomas, 49 other tumors, 11 cerebrovascular diseases, and 2 functional diseases. The feasibility and usefulness of the integrated theater were evaluated for individual diseases, focusing on whether intraoperative images (including diffusion tensor imaging) affected the surgical strategy. The extent of resection and outcomes in each histological category of brain tumors were examined. Intraoperative high-field MR imaging frequently affected or modified the surgical strategy in the glioma group (27/38 cases, 71.1%), but less in the other tumor group (13/49 cases, 26.5%). The surgical strategy was not modified in cerebrovascular or functional diseases, but the success of procedures and the absence of complications could be confirmed. In glioma surgery, subtotal or greater resection was achieved in 22 of the 31 patients (71%) excluding biopsies, and intraoperative images revealed tumor remnants resulting in the extension of resection in 21 of the 22 patients (95.4%), the highest rate of extension among all types of pathologies. The integrated neuro-navigation improved workflow. The best indication for intraoperative high-field MR imaging and integrated neuro-navigation is brain tumors, especially gliomas, and is supplementary in assuring quality in surgery for cerebrovascular or functional diseases. Immediate quality assurance is provided in several types of neurosurgical procedures.

Transsphenoidal pituitary macroadenomas resection guided by PoleStar N20 low-field intraoperative magnetic resonance imaging: comparison with early postoperative high-field magnetic resonance imaging.

OBJECTIVE: To evaluate the applicability of low-field intraoperative magnetic resonance imaging (iMRI) during transsphenoidal surgery of pituitary macroadenomas. METHODS: Fifty-five transsphenoidal surgeries were performed for macroadenomas (modified Hardy's Grade II-IV) resections. All of the surgical processes were guided by real-time updated contrast T1-weighted coronal and sagittal images, which were acquired with 0.15 Tesla PoleStar N20 iMRI (Medtronic Navigation, Louisville, CO). The definitive benefits as well as major drawbacks of low-field iMRI in transsphenoidal surgery were assessed with respect to intraoperative imaging, tumor resection control, comparison with early postoperative high-field magnetic resonance imaging, and follow-up outcomes. RESULTS: Intraoperative imaging revealed residual tumor and guided extended tumor resection in 17 of 55 cases. As a result, the percentage of gross total removal of macroadenomas increased from 58.2% to 83.6%. The accuracy of imaging evaluation of low-field iMRI was 81.8%, compared with early postoperative high-field MRI (Correlation coefficient, 0.677; P < 0.001). A significantly lower accuracy was identified with low-field iMRI in 6 cases with cavernous sinus invasion (33.3%) in contrast to the 87.8% found with other sites (Fisher's exact test, P < 0.001). CONCLUSION: The PoleStar N20 low-field iMRI navigation system is a promising tool for safe, minimally invasive, endonasal, transsphenoidal pituitary macroadenomas resection. It enables neurosurgeons to control the extent of tumor resection, particularly for suprasellar tumors, ensuring surgical accuracy and safety, and leading to a decreased likelihood of repeat surgeries. However, this technology is still not satisfying in estimating the amount of the parasellar residual tumor invading into cavernous sinus, given the false or uncertain images generated by low-field iMRI in this region, which are difficult to discriminate between tumor remnant and blood within the venous sinus.

[A simple-irrigating system for endoscopic sinus surgery]. / Zastosowanie prostego systemu pluczacego w chirurgii endoskopowej nosa i zatok przynosowych.

INTRODUCTION: The most troublesome problem during endoscopic surgery is fouling of the endoscope lens (tip) with blood. Irrigating systems are available on the market but they are relatively very expensive. We present our own simple irrigating system, very effective and inexpensive. MATERIAL AND METHODS: The system consists of: polyethylene catheter No 6, sterile intravenous line with interposed stopcock, 500 ml saline solution, endoscope. The catheter is fixed to the endoscope with sterile sticks and connected to the bottle of saline solution with intravenous line. During the operation the irrigant solution flow is controlled with interposed stopcock. CONCLUSIONS: A simple irrigating system allows cleaning of blood from the endoscope obviating the need for frequent removal of the endoscope from the nose. This allows more rapid and safer endoscopic surgery. It is very simple and cheap.

The use of the SonoSite ultrasound device for intraoperative evaluation of the aorta.

OBJECTIVE: Neurologic complications remain a significant cause of morbidity and mortality in cardiac surgery. Risk factors for neurologic injuries include the presence of atheromatous disease in the aorta. Epiaortic ultrasound has been shown to be superior in detecting the extent and location of atheromatous disease. The SonoSite Corporation (Bothell, WA) has recently introduced an affordable, portable, high-resolution ultrasound device. This new device was compared with the Hewlett-Packard Sonos 5550 ultrasound device (currently manufactured by Philips, Andover, MA) to determine suitability for this purpose. DESIGN: Prospective, serial comparison of 2 devices. SETTING: University hospital. PARTICIPANTS: Fifty consecutive cardiac surgery patients. INTERVENTIONS: Intraoperative epiaortic ultrasound images were obtained using a SonoSite 180 Plus ultrasound device and a Hewlett-Packard Sonos 5500 ultrasound device. Three observers graded recorded images based on extent of atheromatous disease. MEASUREMENTS AND MAIN RESULTS: Two patients were excluded because of errors in recording images. For the 48 remaining patients, consensus (median) grades had an observed agreement of 93.6% compared with a chance agreement of 67.7%. This correlates to a kappa value of 0.80 or near-excellent agreement. CONCLUSIONS: The near-excellent agreement of the 2 devices is acceptable, thus providing a unique opportunity to expand the use of epiaortic ultrasound imaging.

La biopsia intraoperatoria: seguridad diagnóstica, experiencia y correlación de resultados / Intraoperative biopsy: diagnostic accuraccy, experience and correlations of results

La biopsia intraoperatoria es una herramienta de apoyo muy valorada por los cirujanos desde hace muchos años. Las indicaciones y contraindicaciones han cambiado en el tiempo y esto hace variar su seguridad diagnóstica. Se analiza una serie de 105 procedimientos consecutivos y se muestran los resultados obtenidos (95,23 por ciento de índice de aciertos, sensibilidad de 86,66 por ciento, especificidad de 98,66 por ciento y valor predictivo de 96,29 por ciento), demostrando que este procedimiento en nuestro medio se mantiene dentro del rango de series de mayores volúmenes y que es plenamente válido, confiable y vigente. Se recomienda que las mediciones de seguridad diagnóstica sean efectuadas periódicamente por los departamentos de Anatomía Patológica y Laboratorios de Histopatología.

Using intraoperative radiation therapy--a case study.

The introduction of a mobile linear accelerator in the OR has made intraoperative radiation therapy (IORT) more plausible. An IORT treatment can deliver a single high dose of radiation to a tumor or tumor bed after surgical resection or surgical exposure of high risk areas. This article details a case study in which IORT was used on a patient with sigmoid carcinoma and the procedure outcomes.

Intra-operative ultrasound guidance of vena caval umbrella placement in a super obese patient.

Morbidly obese patients are often denied the benefits of sophisticated diagnostic studies and interventions because of the maximum weight limits of available equipment. Two examples in our hospital include a limit of 227 kg (500 lb) on our CT and angiographic tables. We present a patient who was considered to be high risk for recurrent pulmonary emboli and who could not undergo preoperative vena caval umbrella placement, because his weight exceeded the limit of our angiographic table. Intraoperative placement of the umbrella was accomplished by ultrasound localization of the device. We offer this alternative as an adjuvant in the armamentarium of the bariatric surgeon.

Intraoperative magnetic resonance: the future of surgery.

Intraoperative magnetic resonance imaging (iMRI) is a new development in medicine that bridges the specialties of surgery and radiology. Deficiencies in the visualization of anatomical architecture and the perception of tumour boundaries in conventional open surgery have led to the integration of imaging within surgery. The superior soft tissue and multiplanar imaging features of magnetic resonance (MR) make this imaging modality superior to that of alternatives. The unique properties of MR to detect heat change and perfusion, and diffusion characteristics of tissue enhance the usefulness of this medium. Concurrent developments in computer aided image guidance and thermoablative technology, herald the era of minimally invasive tumour ablation. Applications have been developed for areas such as neurosurgery, general surgery, gynaecology and urology.

Intraoperative measurement of lumbar spine motion segment stiffness.

STUDY DESIGN: Prospective trial. OBJECTIVES: To test an intraoperative diagnostic tool to determine if it provided the surgeon with a safe, reproducible, accurate, quantitative measure of lumbar spine motion segment stability. SUMMARY OF BACKGROUND DATA: Several devices have been developed to measure motion segment stiffness, however, few have been tested intraoperatively on humans, and none, to the best of the authors' knowledge have been tested as extensively as the device described in this study. Objective criteria, such as those provided by an intraoperative gauge, can be helpful in determining when and what type of fusion of a degenerated spinal motion segment unit should be performed following decompressive surgery. METHODS: The spinal stiffness gauge, placed between spinous processes of adjacent vertebrae, applies a controlled, constant loading rate along the spine's longitudinal axis, producing a load-displacement curve from which stiffness, range of motion, and hysteresis can be computed. Measurements from this tool were then used to investigate differences in stiffness of the motion segment before and after decompressive surgery, between spine levels, and between male and female subjects. RESULTS: The spinal stiffness gauge stiffness measurements correlated with the surgeon's subjective stiffness measurements on the same motion segments. The stiffness measurements had excellent repeatability. Stiffness was dependent on the spine level, gender, and degree of disc degeneration. CONCLUSIONS: This study demonstrated the efficacy of the spinal stiffness gauge for providing an objective, quantitative, intraoperative stiffness (stability) measurement of the lumbar spine motion segment.

The clinical usefulness of intraoperative spinal stiffness measurements.

STUDY DESIGN: Determination of clinical results at least 2 years after lumbar spine surgery during which spinal stiffness measurements were made. OBJECTIVES: To determine whether spine stiffness is predictive of clinical results after lumbar spine surgery for spinal stenosis, disc herniation, or degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: The implied clinical wisdom is that instability of the spine portends a poor prognosis for relief of back pain after surgery in the absence of a fusion. The possibility that an objective measure of lumbar spinal motion segment unit stiffness could aid the surgeon in predicting satisfaction with treatment was considered. METHODS: A total of 298 patients were measured intraoperatively with the spinal stiffness gauge to determine motion segment stiffness. Intraoperative spinal stiffness was analyzed to determine the influence of this measurement on clinical results. RESULTS: Statistical analysis revealed that stiffness measurements did not correlate with clinical results of surgery. Patients with loose motion segment units before decompression did not demonstrate a significantly different level of satisfaction with surgical results a minimum of 2 years after surgery, whether they were fused or not fused. Based on stiffness measurements, a diagnosis of herniated nucleus pulposus or degenerative spondylolisthesis was indicative of a more unstable spine than a diagnosis of spinal stenosis. CONCLUSIONS: Intraoperative spinal stiffness measurements did not predict clinical results after lumbar spine surgery.

Contribuiçao técnica à histerectomia abdominal / Technical contribution to abdominal hysterectomy

A histerectomia abdominal apresenta como complicaçao mais frequente a infecçao da ferida operatória. Os autores descrevem uma técnica que pode diminuir a incidência de complicaçoes infecciosas pós-operatórias em histerectomias abdominais. A técnica envolve o emprego de um aspirador cirúrgico na vagina, de forma a impedir a contaminaçao da pelve a partir de secreçoes da vagina

Endo-neuro-sonography: anatomic aspects of the ventricles.

To evaluate the usefulness of transendoscopic sonography, we have studied the use of a new sonographic probe of 6 F diameter in 11 fresh specimens. We achieved a precise imaging of well known anatomic structures and, moreover, obtained an additional dimension in endoscopy, since the sonographic probe adds a transverse scan to the endoscopic view, like a mini-CT at the tip of the probe. In this way, we also examined the guiding characteristics of this imaging technique, both in real time and on-line. Our results promise further interesting aspects of this technique in minimally invasive neurosurgery and suggest that further development and clinical experience seem to be justified.

Intraportal endovascular ultrasonography as a new diagnostic procedure in pancreatic surgery.

BACKGROUND/AIMS: This presents the results of a prospective study on the use of intraportal endovascular ultrasonography (IPEUS) as a screening tool for pancreatic carcinoma. PATIENTS AND METHODS: Twenty-four patients with pancreatic cancer (17 head, 7 body) were studied for portal vein invasion using intraportal endovascular ultrasonography (IPEUS). In 22 cases, IPEUS was performed intraoperatively from the superior mesenteric venous route with an 8-French, 20 MHz intravascular ultrasound (IVUS) catheter, in two cases preoperatively from the percutaneous transhepatic route with a 6- French, 20 MHz IVUS catheter. The sonographic criterion for detection of portal venous invasion was obliteration of the echogenic band of the portal vein. The IPEUS results were compared with those of CT and portography. RESULTS: Vascular invasion was confirmed with resected specimens in nine cases and with operative findings in three patients. For diagnosis of portal venous invasion, the sensitivity, specificity, and overall accuracy of IPEUS were 100%, 91.7%, and 95.8% respectively. For portography, the equivalent values were 66.7%, 75%, and 70.8%, while those for CT were 75%, 66.7%, and 70.8%.

Anestesia con bruprenorfina, isofluorona y lidocaína en pacientes neuroquirúrgicos / Buprenorphine, isofluorane and lidocaine for anesthesia in neurosurgical patients

La anestesia general balanceada es empleada frecuentemente en neuroanestesia. En el presente trabajo, se utilizó un opioide agonista-antagonista (buprenorfina) en dosis única, en combinación con isofluorano y lidocaína en infusión en pacientes sometidos a diversos procedimientos neuroquirúrgicos. Se estudiaron sus efectos sobre la PaO2, la saturación de O2 y la PaCO2, durante la inducción, y la calidad de la anestesia basados en el comportamiento hemodinámico y las condiciones del tejido cerebral. La buprenorfina produjo a dosis de 5µg/kg disminución de la PaO2, la saturación de O2, e incremento de la PaCO2 en el paciente con ventilación espontánea. En lo que respecta a la calidad de la anestesia podemos considerarla buena puesto que los pacientes presentaron estabilidad hemodinámica y las condiciones del tejido cerebral fueron adecuadas en un alto porcentaje de los pacientes. La causa de que en algunos pacientes el tejido cerebral no se encontrará en buenas condiciones fue principalmente la patología propia de los mismos y no al uso de la buprenorfina

The design, construction and clinical evaluation of a small phased array transducer for intraoperative echocardiography.

A small probe for cardiac surgery was developed and clinically tested. The probe is built as a phased array transducer with 64 elements with a centerfrequency of 5 MHz. The transducertip is connected with a handle by a flexible yet steerable shaft. This shaft has a length of 10 cm and can be set in a desired shape. Good quality images were obtained in all patients. The first study suggest many applications for a small probe in intraoperative echocardiography.