Sanju Lama

The Evolution of neuroArm

Intraoperative imaging disrupts the rhythm of surgery despite providing an excellent opportunity for surgical monitoring and assessment. To allow surgery within real-time images, neuroArm, a teleoperated surgical robotic system, was conceptualized. The objective was to design and manufacture a magnetic resonance-compatible robot with a human-machine interface that could reproduce some of the sight, sound, and touch of surgery at a remote workstation. University of Calgary researchers worked with MacDonald, Dettwiler and Associates engineers to produce a requirements document, preliminary design review, and critical design review, followed by the manufacture, preclinical testing, and clinical integration of neuroArm. During the preliminary design review, the scope of the neuroArm project changed to performing microsurgery outside the magnet and stereotaxy inside the bore. neuroArm was successfully manufactured and installed in an intraoperative magnetic resonance imaging operating room. neuroArm was clinically integrated into 35 cases in a graded fashion. As a result of this experience, neuroArm II is in development, and advances in technology will allow microsurgery within the bore of the magnet. neuroArm represents a successful interdisciplinary collaboration. It has positive implications for the future of robotic technology in neurosurgery in that the precision and accuracy of robots will continue to augment human capability.

Merging machines with microsurgery: clinical experience with neuroArm

OBJECT It has been over a decade since the introduction of the da Vinci Surgical System into surgery. Since then, technology has been advancing at an exponential rate, and newer surgical robots are becoming increasingly sophisticated, which could greatly impact the performance of surgery. NeuroArm is one such robotic system. METHODS Clinical integration of neuroArm, an MR-compatible image-guided robot, into surgical procedure has been developed over a prospective series of 35 cases with varying pathology. RESULTS Only 1 adverse event was encountered in the first 35 neuroArm cases, with no patient injury. The adverse event was uncontrolled motion of the left neuroArm manipulator, which was corrected through a rigorous safety review procedure. Surgeons used a graded approach to introducing neuroArm into surgery, with routine dissection of the tumor-brain interface occurring over the last 15 cases. The use of neuroArm for routine dissection shows that robotic technology can be successfully integrated into microsurgery. Karnofsky performance status scores were significantly improved postoperatively and at 12-week follow-up. CONCLUSIONS Surgical robots have the potential to improve surgical precision and accuracy through motion scaling and tremor filters, although human surgeons currently possess superior speed and dexterity. Additionally, neuroArms workstation has positive implications for technology management and surgical education. NeuroArm is a step toward a future in which a variety of machines are merged with medicine.

Robotics in the neurosurgical treatment of glioma.

Background: The treatment of glioma remains a significant challenge with high recurrence rates, morbidity, and mortality. Merging image guided robotic technology with microsurgery adds a new dimension as they relate to surgical ergonomics, patient safety, precision, and accuracy. Methods: An image-guided robot, called neuroArm, has been integrated into the neurosurgical operating room, and used to augment the surgical treatment of glioma in 18 patients. A case study illustrates the specialized technical features of a teleoperated robotic system that could well enhance the performance of surgery. Furthermore, unique positional and force information of the bipolar forceps during surgery were recorded and analyzed. Results: The workspace of the bipolar forceps in this robot-assisted glioma resection was found to be 25 × 50 × 50 mm. Maximum values of the force components were 1.37, 1.84, and 2.01 N along x, y, and z axes, respectively. The maximum total force was 2.45 N. The results indicate that the majority of the applied forces were less than 0.6 N. Conclusion: Robotic surgical systems can potentially increase safety and performance of surgical operation via novel features such as virtual fixtures, augmented force feedback, and haptic high-force warning system. The case study using neuroArm robot to resect a glioma, for the first time, showed the positional information of surgeons hand movement and tool-tissue interaction forces.

Forces exerted during microneurosurgery: a cadaver study

A prerequisite for the successful design and use of robots in neurosurgery is knowledge of the forces exerted by surgeons during neurosurgical procedures. The aim of the present cadaver study was to measure the surgical instrument forces exerted during microneurosurgery.

Lactate Storm Marks Cerebral Metabolism following Brain Trauma

Background: In brain metabolism, neurons are fueled by lactate passed to them by glia in a metabolic coupling. Results: Following brain trauma, lactate uptake into neurons from glia was impaired, producing a metabolic lactate storm. Conclusion: Brain trauma results in neuronal-glial metabolic uncoupling, releasing free lactate. Significance: Inhibition of lactate production or its removal may be an important therapeutic strategy for brain trauma. Brain metabolism is thought to be maintained by neuronal-glial metabolic coupling. Glia take up glutamate from the synaptic cleft for conversion into glutamine, triggering glial glycolysis and lactate production. This lactate is shuttled into neurons and further metabolized. The origin and role of lactate in severe traumatic brain injury (TBI) remains controversial. Using a modified weight drop model of severe TBI and magnetic resonance (MR) spectroscopy with infusion of 13C-labeled glucose, lactate, and acetate, the present study investigated the possibility that neuronal-glial metabolism is uncoupled following severe TBI. Histopathology of the model showed severe brain injury with subarachnoid and hemorrhage together with glial cell activation and positive staining for Tau at 90 min post-trauma. High resolution MR spectroscopy of brain metabolites revealed significant labeling of lactate at C-3 and C-2 irrespective of the infused substrates. Increased 13C-labeled lactate in all study groups in the absence of ischemia implied activated astrocytic glycolysis and production of lactate with failure of neuronal uptake (i.e. a loss of glial sensing for glutamate). The early increase in extracellular lactate in severe TBI with the injured neurons rendered unable to pick it up probably contributes to a rapid progression toward irreversible injury and pan-necrosis. Hence, a method to detect and scavenge the excess extracellular lactate on site or early following severe TBI may be a potential primary therapeutic measure.

Quantification of Forces During a Neurosurgical Procedure: A Pilot Study

OBJECTIVE Knowledge of tool-tissue interaction is mostly taught and learned in a qualitative manner because a means to quantify the technical aspects of neurosurgery is currently lacking. Neurosurgeons typically require years of hands-on experience, together with multiple initial trial and error, to master the optimal force needed during the performance of neurosurgical tasks. The aim of this pilot study was to develop a novel force-sensing bipolar forceps for neurosurgery and obtain preliminary data on specific tasks performed on cadaveric brains. METHODS A novel force-sensing bipolar forceps capable of measuring coagulation and dissection forces was designed and developed by installing strain gauges along the length of the bipolar forceps prongs. The forceps was used in 3 cadaveric brain experiments and forces applied by an experienced neurosurgeon for 10 surgical tasks across the 3 experiments were quantified. RESULTS Maximal peak (effective) forces of 1.35 N and 1.16 N were observed for dissection (opening) and coagulation (closing) tasks, respectively. More than 70% of forces applied during the neurosurgical tasks were less than 0.3 N. Mean peak forces ranged between 0.10 N and 0.41 N for coagulation of scalp vessels and pia-arachnoid, respectively, and varied from 0.16 N for dissection of small cortical vessel to 0.65 N for dissection of the optic chiasm. CONCLUSIONS The force-sensing bipolar forceps were able to successfully measure and record real-time tool-tissue interaction throughout the 3 experiments. This pilot study serves as a first step toward quantification of tool-tissue interaction forces in neurosurgery for training and improvement of instrument handling skills.

Controversy in the management of lenticulostriate artery dissecting aneurysm: a case report and review of the literature.

BACKGROUND Intracranial arterial dissection is an uncommon but well-recognized entity. Treatment remains variable, ranging from observation to intervention via the use of either surgical or endovascular techniques. Aneurysms along the lenticulostriate artery have been reported in only 41 patients. With the current case study we illustrate the effectiveness of observation in the context of a dissecting lenticulostriate aneurysm and discuss other approaches that have been used in the treatment of this particular entity. CLINICAL SUMMARY An accomplished mountain climber presented, after coitus, with acute headache, mild facial weakness, and forgetfulness. Vascular imaging studies revealed a right putaminal hemorrhage secondary to a 3-mm lenticulostriate artery dissecting aneurysm. Clinically, the patient did well, with marked improvement in presenting symptoms enabling his return to mountain climbing. Follow-up angiography showed spontaneous resolution of the arterial dissecting aneurysm. Among the 41 reported cases, 19 were idiopathic, 5 associated with hypertension, and 17 related to various conditions such as Moyamoya disease, arteriovenous malformation, systemic vasculitis, intraventricular tumor, or substance abuse. Of the 42 cases, including the present case, 28 were surgically or endovascularly managed and 12 observed. Only one of the reported cases, a 33-year-old man with Moyamoya disease, who was managed conservatively, died of rebleeding. CONCLUSION There is no common consensus in the literature on a single treatment strategy for a lenticulostriate artery aneurysm. The present case illustrates that observation and follow-up vascular imaging can be an important treatment strategy, allowing healing of the vessel wall and disappearance of the dissecting aneurysm.

A Force-Sensing Bipolar Forceps to Quantify Tool–Tissue Interaction Forces in Microsurgery

The ability to exert an appropriate amount of force on brain tissue during surgery is an important component of instrument handling. It allows surgeons to achieve the surgical objective effectively while maintaining a safe level of force in tool-tissue interaction. At the present time, this knowledge, and hence skill, is acquired through experience and is qualitatively conveyed from an expert surgeon to trainees. These forces can be assessed quantitatively by retrofitting surgical tools with sensors, thus providing a mechanism for improved performance and safety of surgery, and enhanced surgical training. This paper presents the development of a force-sensing bipolar forceps, with installation of a sensory system, that is able to measure and record interaction forces between the forceps tips and brain tissue in real time. This research is an extension of a previous research where a bipolar forceps was instrumented to measure dissection and coagulation forces applied in a single direction. Here, a planar forceps with two sets of strain gauges in two orthogonal directions was developed to enable measuring the forces with a higher accuracy. Implementation of two strain gauges allowed compensation of strain values due to deformations of the forceps in other directions (axial stiffening) and provided more accurate forces during microsurgery. An experienced neurosurgeon performed five neurosurgical tasks using the axial setup and repeated the same tasks using the planar device. The experiments were performed on cadaveric brains. Both setups were shown to be capable of measuring real-time interaction forces. Comparing the two setups, under the same experimental condition, indicated that the peak and mean forces quantified by planar forceps were at least 7% and 10% less than those of axial tool, respectively; therefore, utilizing readings of all strain gauges in planar forceps provides more accurate values of both peak and mean forces than axial forceps. Cross-correlation analysis between the two force signals obtained, one from each cadaveric practice, showed a high similarity between the two force signals.

Quantifying workspace and forces of surgical dissection during robot-assisted neurosurgery.

A prerequisite for successful robot‐assisted neurosurgery is to use a hand‐controller matched with characteristics of real robotic microsurgery. This study reports quantified data pertaining to the required workspace and exerted forces of surgical tools during robot‐assisted microsurgery.

Cerebral expression of DNA repair protein, Ku70, and its association with cell proliferation following cerebral hypoxia–ischemia in neonatal rats

We hypothesized that increased Ku70 expression could be involved in recovery following cerebral hypoxia–ischemia. We investigated the progression of cerebral alterations in Ku70 expression at different time points (24 h, 72 h, 1 week, 4 weeks and 8 weeks) after hypoxia–ischemia (right carotid artery occlusion plus 1.5 h of hypoxia) in neonatal rats. To determine whether in addition to its known role of DNA repair, Ku70 was associated with cell death or cell proliferation we performed double staining for Ku70 and DNA fragmentation or bromodeoxyuridine, respectively. The results show that Ku70 expression was increased in the infarct core and peri‐infarct regions at 24 h following hypoxia–ischemia. The increased Ku70 expression was transient in the infarct core with a loss of Ku70 positive cells over days. In contrast, in the peri‐infarct region the expression of Ku70 remained increased at chronic times 8 weeks following the insult. Cells positive for DNA fragmentation were not co‐localized with cells positive for Ku70 after an insult. However, most of the cells positive for bromodeoxyuridine indicative of cell proliferation were positive for Ku70 in the peri‐infarct region at 8 weeks after the insult. Considering the roles of Ku70 in DNA repair or inhibiting apoptosis and its co‐localization within cells that had undergone proliferation, Ku70 may be considered a potential novel target to enhance recovery following hypoxia–ischemia.