Newly developed electromagnetic tracked flexible neuroendoscope

A clinical study of high-dose urokinase for the treatment of the patients with hypertension induced ventricular hemorrhage

OBJECTIVE

This study discusses the therapeutic effect of high-dose urokinase treatment for hypertension ventricular hemorrhage.

METHODS

A total of 60 patients with hypertension ventricular hemorrhage were randomly assigned to two groups: treatment group (n=30) and control group (n=30). Both groups received bilateral external ventricular drain. The treatment group was injected with 50,000IU urokinase to the lateral ventricle every day; the total injection volume per day was 100,000IU. The control group was injected with 20,000IU urokinase to the lateral ventricle every day with a total injection volume per day of 40,000IU. Lumbar puncture was performed in both groups after the later ventricular drain was removed to release cerebrospinal fluid (CSF). Head Computed tomography(CT) examination was performed regularly to observe changes in the ventricular hematoma as well as the occurrence of complications such as intracranial infection and hydrocephalus. Patient prognosis 6 weeks after surgery was compared between the two groups.

RESULTS

In the treatment group, the intraventricular hemorrhage clearance time and the number of instances of urokinase treatment were significantly less than those of the control group (P<0.05). The total urokinase dosage of the treatment group was significantly higher than that of the control group (P<0.05). With respect to post-surgery complications, in the treatment group, there were three cases of hydrocephalus and one case of intracranial infection. In the control group, there were four cases of hydrocephalus and three cases of intracranial infection. Intraventricular re-hemorrhage was not observed in either group. Intracranial infection was relieved after strengthened anti-infective therapy and continuous drainage. There was a statistically significant difference in the occurrence of complications between the treatment group and the control group (P<0.05). The rate of good prognosis in the treatment group was higher than that of the control group (P<0.05), and the inefficiency rate was lower (P<0.05).

CONCLUSIONS

High-dose urokinase treatment produces a significant therapeutic effect in hypertension ventricular hemorrhage. This treatment can quickly eliminate intraventricular hemorrhage, shorten the ventricular drain tube indwelling time, decrease the occurrence of intracranial infection, and increase the likelihood of a good prognosis.

A Novel Approach of Navigation-Assisted Flexible Neuroendoscopy

BACKGROUND AND IMPORTANCE

Neuronavigation-assisted endoscopy is commonly used for skull base and intraventricular surgery. Flexible neuroendoscopy offers certain advantages over rigid endoscopy; however, a major disadvantage of the flexible endoscope has been easy disorientation in the flexed position. Neuronavigation-assisted flexible neuroendoscopy was not available until now. This is the first report of the use of navigation-assisted flexible neuroendoscopy in a patient with hydrocephalus.

CLINICAL PRESENTATION

A 10-mo-old girl presented with irritability and vomiting to the emergency department and was found to have severe hydrocephalus. The patient underwent successful endoscopic third ventriculostomy and exploration of the ventricles (lateral, third, cerebral aqueduct, fourth) and basal cisterns with the flexible neuroendoscopy assisted with electromagnetic neuronavigation.

CONCLUSION

As demonstrated by this initial experience, neuronavigation-assisted flexible neuroendoscopy is a feasible and safe tool, endoscopic procedures with the flexible endoscope may be possible in a safer manner. We report the first use of neuronavigation-assisted flexible neuroendoscopy to perform an ETV and exploration of the entire ventricular system. Further evaluation will be necessary to define and expand its applications in neurosurgery.

Assessment of the Accuracy and Errors of Head-Up Display by an Optical Neuronavigation System in Brain Tumor Surgery

BACKGROUND: A head-up display (HUD) in which navigational information is projected into the microscope view may enable surgeons to perform operations more efficiently. Projecting depictions of both tumor and important intracranial structures on the HUD may facilitate safe surgery.

OBJECTIVE: To investigate accuracy and errors regarding important intracranial structures, errors due to brain shifts, and preservation rates for important intracranial structures.

METHODS: A total of 184 surgeries in 172 patients were performed using this operation system. Postoperatively, we determined accuracy and errors for actual structures and virtual reality on the HUD and performed statistical analyses.

RESULTS: Preresection accuracy for important intracranial structures was highest for the internal carotid artery (ICA; 90.4%) and lowest for the posterior inferior cerebellar artery (53.6%). Differences between pre- and postresection accuracy were greatest, in descending order, for the cortical vein (P &lt; .0001), V4 segment of vertebral artery (P &lt; .0001), and anterior inferior cerebellar artery (P = .00780), whereas differences between pre- and postresection errors were smallest for the cranial nerve V (P = .500), middle cerebral artery (P = .0313), and ICA (P = .0313). Cases of poor preresection accuracy and large differences in pre- to postresection accuracy were seen in the prone position.

CONCLUSION: A reliable surgical resection rate was achieved using the HUD, and reliable preservation of important intracranial structures was also possible. Accuracy was concluded to be within an acceptable range.

Aspiration of parafalcine empyemas with flexible scope

PURPOSE

Subdural empyemas are considered neurosurgical emergencies, and the parafalcine location is particularly insidious. We revised the experience of general surgeons who are used to manage chronic pleural purulent collections with video-assisted thoracoscopy.

METHODS

With a similar technique, we successfully aspirated a parafalcine empyema using a flexible scope avoiding a more invasive craniotomy. A review of the treatment options of empyematous collections is also provided, focusing particularly on the hazardous parafalcine location.

RESULTS

The management of subdural empyemas poses different decision-making problems compared to common brain abscesses, urging a more rapid and holistic surgical treatment with minimally invasive approach. Endoscopic aspiration of parafalcine empyema was followed by complete recovery in our patient.

CONCLUSIONS

Flexible endoscopy is a promising method to obtain complete pus removal even from loculated collections through a bur hole, avoiding large craniotomies and consequent potential complications.

Novel ureteroscopic navigation system with a magnetic tracking device: a preliminary ex vivo evaluation

PURPOSE

Examination of the pyelocaliceal system using a flexible ureteroscope necessitates accurate orientation of the tip of the instrument. This study assessed the use of a novel real-time ureteroscopic navigation system in a pyelocaliceal phantom.

MATERIALS AND METHODS

The navigation system used a magnetic tracking device to determine the position of the ureteroscope in a pyelocaliceal phantom and displayed the position of the endoscope on a three-dimensional image that could be rotated. Twenty-eight urologists were divided into group A and group B (seven novice surgeons and seven experienced surgeons in each group). All participants were asked to examine the phantom and identify the positions of three designated calices, without the navigation system (Task 1) and with the navigation system (Task 2). In group A, participants performed Task 1 followed by Task 2. In group B, participants performed Task 2 followed by Task 1. The accuracy rate (AR) of identifying the calices, migration length (ML) of the tip of the ureteroscope, and time (T) taken to complete the task were recorded. The results were compared between Task 1 and Task 2, and between novice and experienced surgeons.

RESULTS

The AR for Task 2 was 100% in both group A and group B. The AR was significantly lower in Task 1 than in Task 2 for both novice and experienced surgeons in both groups (group A: novice P=0.016, experienced P=0.034; group B: novice P=0.015, experienced P=0.015; Wilcoxon test). In Group A, T was significantly longer in Task 1 than in Task 2 for experienced surgeons. There were no significant differences in ML or T between novice and experienced surgeons.

CONCLUSIONS

Our novel ureteroscopic navigation system improved the accuracy of ureteroscopic maneuvers. Further development of this system for use in clinical ureteroscopic procedures is planned.

An adaptive 6-DOF tracking method by hybrid sensing for ultrasonic endoscopes

In this paper, a novel hybrid sensing method for tracking an ultrasonic endoscope within the gastrointestinal (GI) track is presented, and the prototype of the tracking system is also developed. We implement 6-DOF localization by sensing integration and information fusion. On the hardware level, a tri-axis gyroscope and accelerometer, and a magnetic angular rate and gravity (MARG) sensor array are attached at the end of endoscopes, and three symmetric cylindrical coils are placed around patients' abdomens. On the algorithm level, an adaptive fast quaternion convergence (AFQC) algorithm is introduced to determine the orientation by fusing inertial/magnetic measurements, in which the effects of magnetic disturbance and acceleration are estimated to gain an adaptive convergence output. A simplified electro-magnetic tracking (SEMT) algorithm for dimensional position is also implemented, which can easily integrate the AFQC's results and magnetic measurements. Subsequently, the average position error is under 0.3 cm by reasonable setting, and the average orientation error is 1° without noise. If magnetic disturbance or acceleration exists, the average orientation error can be controlled to less than 3.5°.