Tumour cell dispersion by the ultrasonic aspirator during brain tumour resection

Mucous Extractor for Tumor Tissue Sampling in Neurosurgery

Objective Collection of sample for histopathological analysis is highly important during any surgical procedure. The histopathology report helps determine the diagnosis, prognosis further management, and follow-up plan. The use of a reliable sample collection technique is doubly important in neurosurgical procedures because lesions are often deep-seated and difficult to access.

Materials and Methods Conventional techniques of sample collection, such as use of tumor-grasping forceps and collection of material from the ultrasonic aspirator device suffer from limitations of access and unreliability. We propose a novel technique of sample collection using readily available mucous aspirator device.

Results This device is economical, sterile, and disposable. It can be used even in low-resource settings because it is easily available. It can also be connected to suction cannula and the negative pressure settings can be adjusted as required.

Conclusion The use of this device for neurosurgical procedures has been tried in the transcranial and transnasal neurosurgical procedures and found to be effective. The sample collected in the canister of the mucous aspirator can be directly sent to the laboratory for histopathological analysis.

Surgical considerations for maximal safe resection of exophytic brainstem glioma in the pediatric age group

Background:

Brainstem glioma is the leading cause of morbidity and mortality among all central nervous system tumors, especially in childhood as it represents about 20% of all pediatric brain tumors. Therefore, this study aimed to present our experience in a tertiary center in a developing country with limited resources for the surgical management of exophytic brainstem gliomas.

Methods:

This retrospective study included pediatric patients with brainstem (midbrain, pontine, or medullary) focal or diffuse gliomas whether low or high grade that had dorsal, ventral, or lateral exophytic component who were presented to our hospitals from January 2019 to January 2021. The patients’ data were collected, such as age, sex, preoperative and postoperative clinical condition, radiological data, surgical approach, extent of tumor removal, histopathology, follow-up period, and adjuvant therapy.

Results:

A total of 23 patients were included in this study. The telovelar approach was used in 17 patients, the supracerebellar infratentorial approach in three patients, and the retrosigmoid, transcerebellar, and occipital transtentorial approach once for each patient. Twenty patients underwent near-total excision, and three underwent subtotal excision. Two-thirds of our cases (17 patients) were low-grade gliomas, with the remaining one-third comprising entirely of either anaplastic astrocytoma (five patients) or glioblastoma multiforme (one patient). The follow-up period of the patients extended from 3 months to 24 months.

Conclusion:

Exophytic brainstem glioma surgery can result in good outcomes with minimal complications when near-total excision is attempted through a properly chosen approach and adherence to some surgical techniques and considerations.

Reconversion of neurosurgical practice in times of the SARS-CoV-2 pandemic: a narrative review of the literature and guideline implementation in a Mexican neurosurgical referral center

OBJECTIVE

The coronavirus disease 2019 (COVID-19) pandemic has forced the modification of surgical practice worldwide. Medical centers have been adapted to provide an efficient arrangement of their economic and human resources. Although neurosurgeons are not in the first line of management and treatment of COVID-19 patients, they take care of patients with neurological pathology and potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, the authors describe their institutional actions against the pandemic and compare these actions with those in peer-reviewed publications.

METHODS

The authors conducted a search using the MEDLINE, PubMed, and Google Scholar databases from the beginning of the pandemic until July 11, 2020, using the following terms: "Neurosurgery," "COVID-19/SARS-CoV-2," "reconversion/modification," "practice," "academy," and "teaching." Then, they created operational guidelines tailored for their institution to maximize resource efficiency and minimize risk for the healthcare personnel.

RESULTS

According to the reviewed literature, the authors defined the following three changes that have had the greatest impact in neurosurgical practice during the COVID-19 pandemic: 1) changes in clinical practices; 2) changes in the medical care setting, including modifications of perioperative care; and 3) changes in the academic teaching methodology.

CONCLUSIONS

The Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" is one of the major referral centers for treating highly complex neurosurgical pathologies in Mexico. Its clinical and neurosurgical practices have been modified with the implementation of specific interventions against the spread of COVID-19. These practical and simple actions are remarkably relevant in the context of the pandemic and can be adopted and suited by other healthcare centers according to their available resources to better prepare for the next event.

Early postoperative MRI after resection of brain metastases-complete tumour resection associated with prolonged survival

BACKGROUND

This study aimed to investigate the incidence of residual tumour after resection of brain metastases using early postoperative magnetic resonance imaging (MRI) and the influence of residual tumour on overall patient survival.

METHODS

Data from 72 consecutive adult patients undergoing surgery for cerebral metastases over an 18-month study period were retrospectively collected. Early postoperative MRI was used to determine the presence of postoperative residual tumour. Patients were divided into three groups according to the presence of tumour remnant on early postoperative MRI: "no residual tumour", "non-measurable residual tumour" and "measurable residual tumour". Survival analysis (mean estimate survival time) was performed using the Kaplan-Meier and log-rank (mantel cox) tests and compared between groups. Surgical reports were evaluated with regard to the surgeon statement about intraoperative extent of resection (EOR) and compared with the presence of tumour remnant found on the early postoperative MRI.

RESULTS

Sixty-eight procedures were followed by early postoperative MRI. MRI verified the presence of "measurable residual tumour" following 15 procedures (22%). MRI confirmed complete resection in 57%. Gross total resection was described by the operating surgeon in 85% of the procedures. There was a significant difference in survival time after surgery between the group having no residual tumour on MRI and the group with measurable residual tumour (p = 0.025). This difference could not be explained by the differences in postoperative radiation therapy. The longest survival was found in patients with non-measurable and no residual tumour on early postoperative MRI, who also received postoperative radiotherapy.

CONCLUSION

Residual tumour was seen on MRI after 22% of the procedures. The intraoperative assessment of EOR performed by the surgeon diverged from the early postoperative MRI in 40% of procedures. Correct assessment of residual tumour thus requires early postoperative MRI. Measurable residual tumour on early postoperative MRI was associated with shorter overall survival independent on postoperative radiotherapy.

Risk for leptomeningeal seeding after resection for brain metastases: implication of tumor location with mode of resection

Object

Surgical spillage has been one of the causative factors for the development of leptomeningeal seeding (LMS) after resection of brain metastases. In this paper, the authors' goal was to define the factors related to the development of LMS and to evaluate the difference according to tumor location.

Methods

The authors retrospectively analyzed 242 patients who had undergone resection for brain metastases. The factors investigated included tumor location with proximity to the CSF pathway (that is, contacting, involved with, or separated from the CSF pathway), the method of resection, and the use of the Cavitron Ultrasonic Surgical Aspirator (CUSA).

Results

A total of 39 patients (16%) developed LMS at a median of 6.0 months (range 1–42 months) after resection. The risk of developing LMS was significantly higher in patients whose tumors were resected piecemeal than in those whose tumors were removed en bloc, with a hazard ratio (HR) of 4.08 (p < 0.01). The incidence of LMS was significantly higher in patients in whom the CUSA was used, and the HR was 2.64 (p < 0.01). The proximity of tumor to the CSF pathway in the involved group conferred an increased risk of LMS compared with the separated group (HR 11.36, p < 0.01). The risk of piecemeal resection for LMS was significant only in involved lesions (p < 0.01), and the use of the CUSA in both contact and involved lesions increased the incidence of LMS (p < 0.01 and p < 0.03, respectively).

Conclusions

The authors suggest that piecemeal resection using the CUSA should be limited because of the risk of postsurgical LMS, especially when the tumor is in contact with the CSF pathway.

Microfenestration using the CUSA Excel ultrasonic aspiration system in chondrodystrophic dogs with thoracolumbar disk extrusion: a descriptive cadaveric and clinical study

OBJECTIVE

To describe an ultrasonic surgical aspirator assisted disk fenestration technique in dogs.

STUDY DESIGN

Descriptive cadaveric and prospective clinical study.

ANIMALS

Fresh Beagle cadavers (n=5) and 10 chondrodystrophic dogs with thoracolumbar disk extrusion.

METHODS

Cadaveric study: Intervertebral disks T12-L2 were fenestrated with the CUSA Excel in 5 Beagle cadavers, and fenestration efficacy assessed by morphologic examination of the completeness of fenestration and size of annulotomy. Clinical study: the affected intervertebral disk was fenestrated in 10 chondrodystrophic dogs treated by hemilaminectomy for thoracolumbar disk disease. Efficacy of fenestration was evaluated.

RESULTS

Mean time necessary to perform CUSA assisted fenestration was 8 minutes (range, 5-10 minutes) for each disk in cadavers and patients. In cadaver spines, removal of the nucleus pulposus was complete in 11/15 disks. In 4 disks, remnants of nucleus pulposus material were observed on the contralateral side. Nuclear material was normal in 9/15 disks and showed evidence of chondroid degeneration on histopathologic examination in the 6 disks. Median annulotomy size was 3 mm. Clinically, no signs of early recurrence were observed and all dogs recovered uneventfully.

CONCLUSIONS

CUSA assisted fenestration is a safe and efficient method of fenestration for removal of most of the nucleus pulposus through a limited annulotomy.

Evaluation of intracranial meningioma resection with a surgical aspirator in dogs: 17 cases (1996-2004)

OBJECTIVE

To determine results of intracranial meningioma resection by use of a surgical aspirator and assess prognostic factors associated with intracranial meningiomas in dogs.

DESIGN

Retrospective case series.

ANIMALS

17 dogs.

PROCEDURES

Medical records of dogs that underwent resection of an intracranial meningioma by use of a surgical aspirator were reviewed. Information pertaining to signalment, imaging findings, clinical signs, duration of clinical signs, preoperative treatment, location of the tumor, results of histologic assessment, outcome, and necropsy results was obtained from the medical record. Clients and referring veterinarians were contacted via telephone for information on recurrence of clinical signs and postoperative survival time.

RESULTS

16 dogs were > 7 years of age, and all 17 dogs had seizures before surgery. The most commonly affected breed was the Golden Retriever, represented by 6 of the 17 dogs. Median survival time was 1,254 days. Of the data collected, only histologic subtype of the tumor was prognostic. Analysis of survival times according to histologic tumor subtypes indicated that the order from most brief to longest was as follows: anaplastic, 0 days; fibroblastic, 10 days; psammomatous, > 313 days; meningothelial, > 523 days; and transitional, 1,254 days.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of a surgical aspirator to resect intracranial meningiomas in dogs was associated with longer survival times than those achieved with traditional surgery alone or traditional surgery combined with radiation therapy. Dogs with meningothelial, psammomatous, or transitional intracranial meningioma subtypes appeared to have a better prognosis than dogs with other subtypes of meningioma.

Use of ultrasonic aspiration for dural opening in cranial reoperations: technical note

OBJECTIVE

Dural detachment from the brain in cranial reoperations has been accomplished previously by selective coagulation and the cutting of brain-dural adhesions. The results of ultrasonic aspiration during tumor surgery or brain cutting procedures led the authors to speculate that the detachment of the dura mater from brain tumors by applying the Cavitron ultrasonic surgical aspirator (Valleylab, Boulder, CO [formerly Cavitron, Inc., Stamford, CT]) to the brain-dura mater interface could be used to reduce bleeding and facilitate dural opening during cranial reoperations.

METHODS

Ten patients underwent a second craniotomy for epilepsy surgery (five cases of extended temporal lobectomy and five cases of extended extratemporal lesionectomy). The use of ultrasonic aspiration and its effects on brain separation from the dura mater were examined.

RESULTS

Intraoperative use of the Cavitron ultrasonic surgical aspirator during dural opening produced immediate blanching of the dura mater and enhanced visualization of the cortical surface without distortion of the brain anatomy.

CONCLUSION

Incremental dural opening and brain visualization is achieved by careful application of ultrasonic aspiration directly into the brain-dura limit, producing immediate regional dural devascularization. Use of this technique reduces cortical and dural bleeding and enhances the ease and effectiveness of brain visualization.

Optimizing outcomes with maximal surgical resection of malignant gliomas

BACKGROUND

Aggressive surgical resection of malignant gliomas is a controversial issue in neurosurgery. Studies with rigorous methodology that fully address this issue have only recently become available.

METHODS

The controversy regarding the role of maximal surgical resection of malignant gliomas is reviewed. The authors discuss surgical techniques and adjunctive technologies that can be utilized to assist in resection of these lesions.

RESULTS

Using current microneurosurgical techniques, it is possible to resect malignant gliomas in gross total fashion. An aggressive approach in which 98% or more of the tumor mass is resected results in a statistically significant survival advantage.

CONCLUSIONS

An aggressive surgical procedure for malignant gliomas can result in increased survival duration for selected groups of patients.