Ventricular Access Utilizing Cutaneous Reference Points: statistical analysis and proposal of a new ventricular entry point

OBJECTIVES

Perform radiological measurements and analysis of normal brain CT scans; delineate a new ventricular entry point from cutaneous landmarks, highlighting the potential surgical implications of these findings.

METHODS

6 radiological distances (AR; BR; AL; BL, C and D) were measured in normal brain CT scans using Horos software. Statistical analysis of the measurements was performed with minitab18 software based on age, sex and side.

RESULTS

132 brain CT scans were analyzed, yielding the following mean results: AR distance: 2.1cm; BR distance: 7 cm; AL distance: 2.1 cm; BL distance: 7.1 cm; C distance: 12.4 cm; D distance: 7 cm; new ventricular entry point: 12.4 cm posterior to the nasion and 2.1 cm lateral to the midline.

CONCLUSION

The freehand technique for accessing the lateral ventricles is a common neurosurgical procedure but is often accompanied by complications. To address this, we suggest a novel entry point for ventricular access, determined by cutaneous reference points. This point is situated 12.4 cm posterior to the nasion along the midline, and 2.1cm lateral to the midline. Although our findings may play a role in presurgical planning for ventricular pathologies, future prospective studies are warranted.

Surgical approach to the treatment of pituicytoma. Report of five cases and a literature review

Background

Pituicytoma (PTs) is a rare tumor of the sella and suprasellar region, derived from the pituicytes of the neurohypophysis, having distinct histological characteristics of glial neoplasms. We reported, the clinical data, neuroimaging studies, surgical approaches and pathology in five patients with PTs and also, we reviewed the literature.

Methods

Retrospective chart from five consecutive patients with PTs treated at one University Hospital from 2016 to 2021 were reviewed. In addition, we conducted a search in PubMed/Medline databases using the term "Pituicytoma". Data regarding age, gender, pathological findings, and treatment modality applied were extracted.

Results

All patients were female, aged 29-63, complaining of headaches, visual loss and field defects, dizziness and normal or abnormal levels of circulating pituitary hormones. Magnetic Resonance Imaging (MRI) showed in all patients a sellar and suprasellar mass, which was removed through an endoscopic transsphenoidal approach. Our third patient had a subtotal resection followed by close observation. Histopathology showed a glial non-infiltrative tumors with spindle cells, and a final diagnosis of pituicytoma was made. After surgery, visual field defects in all patients were normalized, and in two patients normal levels of plasma hormones were restored. After a mean of three years follow-up, the patients were managed post-operatively through close clinical observation and serial MRI. None of the patients had recurrence of the disease.

Conclusion

PTs is a rare glial tumor of the sellar and suprasellar region that arises from neurohypophyseal pituicytes. Disease control may be achieved by total excision.

RISK FACTORS RELATED TO TRANSIENT DIABETES INSIPIDUS DEVELOPMENT FOLLOWING TRANSSPHENOIDAL PITUITARY ADENOMA RESECTION: A MULTICENTRIC STUDY

OBJECTIVE

To analyze and find risk factors associated with developing transient diabetes insipidus (DI) using a multicenter case series after transsphenoidal surgery (TSS).

MATERIALS AND METHODS

Medical records of patients who underwent TSS for pituitary adenoma (PA) resection between 2010-2021 at three different neurosurgical centers by four experienced neurosurgeons were retrospectively analyzed. The patients were divided into two groups (DI Group or Control Group). Logistic regression analysis was conducted to identify risk factors associated with postoperative DI. Univariate logistic regression was performed to identify variables of interest. Covariates with a p-value < 0.05 were incorporated into multivariate logistic regression models to identify independently associated risk factors for DI. All statistical tests were conducted using RStudio.

RESULTS

A total of 344 patients were included; 68% were women, the mean age was 46.5 years, and non-functioning adenomas were the most frequent (171, 49.7%). The mean tumor size was 20.3 mm. Covariates associated with postoperative DI were age, female gender and gross total resection (GTR). The multivariable model showed that age (OR 0.97, CI 0.95-0.99, p=0.017) and female gender (OR 2.92, CI 1.50-6.03, p=0.002) remained significant predictors of DI development. GTR was no longer a significant predictor of DI in the multivariable model (OR 1.86, CI 0.99-3.71, p=0.063), suggesting that this variable may be confounded by other factors.

CONCLUSIONS

The independent risk factors for the development of transient DI were female and young patients.

A new, readily accessed and low-cost, device for treating depressed ping pong fractures non-surgically: Technical note

OBJECTIVE

The aim of this paper is to describe a low-cost and readily accessed Manual Aspiration Reduction System (MARS) for use treating ping-pong fractures in three patients.

METHODS

The MARS is composed of a pediatric anesthesia mask, part of a macro dripper, a 3-way stopcock, and two 60-ml syringes. Prior to its use in our patient, the system was tested on five adult volunteers to maximum negative pressure, and none reported pain during the procedure or experienced any other complication. We present three clinical cases of patients with depressed ping-pong fracture who were treated with the MARS at the bedside without anesthesia. The patients were monitored by the neonatology team throughout the procedure.

RESULTS

Skull radiography revealed reduction of the fracture after the procedure performed with the MARS in all patients. The transfontanellar ultrasound and follow-up neurological examination were normal. The patient progressed favorably and was discharged from our service after 24 h.

CONCLUSIONS

Due to its components, the MARS is a low-cost and readily accessed system. In this case, it permitted satisfactory reduction of a ping-pong fracture in all patients. This system should greatly simplify the treatment of such fractures.

A new, low-cost device to treat depressed "ping-pong" fractures non-surgically: technical note

OBJECTIVE

The aim of this paper is to describe a low-cost and readily accessed Manual Aspiration Reduction System (MARS) for use treating neonatal ping-pong fractures.

METHODS

The MARS is composed of a pediatric anesthesia mask, part of a macro dripper, a 3-way stopcock, and two 60-ml syringes. Prior to its use in our patient, the system was tested on five adult volunteers to maximum negative pressure, and none reported pain during the procedure or experienced any other complication.

CLINICAL CASE

A 15-day-old premature girl presented with a congenital ping-pong fracture. Her skull X-ray revealed a right parietal fracture. Neurological examination and transfontanellar ultrasound were normal. Treatment using the MARS was performed at the patient's bedside without sedation or anesthesia. The patient was monitored by the neonatology team throughout.

RESULTS

Skull radiography revealed reduction of the fracture after the procedure performed with the MARS. The transfontanellar ultrasound and follow-up neurological examination were normal. The patient progressed favorably and was discharged from our service after 24 h.

CONCLUSIONS

Due to its components, the MARS is a low-cost and readily accessed system. In this case, it permitted satisfactory reduction of a ping-pong parietal fracture. This system should greatly simplify the treatment of such fractures.

Microsurgical Anatomy and Approaches to the Cerebral Central Core

OBJECTIVE

Through a cadaveric study, we divided the cerebral central core (CCC) into different areas and have proposed a corresponding neurosurgical approach for each sector. As a secondary objective, we analyzed the cortical and subcortical microsurgical anatomy of the CCC. The CCC includes the insula, extreme capsule, claustrum, external capsule, lenticular nucleus, internal capsule, caudate nucleus, and thalamus.

METHODS

Twelve adult human brain hemispheres and one cadaveric head specimen were dissected and studied at the Laboratory of Neuroanatomic Microsurgical of the University of Buenos Aires. Nine cases of CCC neurosurgical pathologies were included in the present study and analyzed. Digital drawings were created of the approaches proposed for each sector of the CCC showing the most relevant surgical details. Photographs of each dissection and measurements obtained were taken.

RESULTS

We divided the CCC into a medial, intermediate, and lateral sector, with specific subdivisions for the lateral and medial sectors. The lateral projection of the foramen of Monro was found deep to the third short gyri of the insula with the following distances: anterior insular limen margin, 23.95 mm; posterior insular limen margin, 22.92 mm; superior limiting sulcus, 14.99 mm, and inferior limiting sulcus, 13.76 mm. We have proposed the following approaches: an ipsilateral transcallosal approach, a contralateral transcallosal approach, a choroidal transfissure approach, a trans-splenial approach, transparietal access entering the intraparietal sulcus, and trans-sylvian approach. The preoperative imaging studies should be analyzed using our method to select the most accurate and safe approach.

CONCLUSIONS

We have provided a description of the limits and anatomy of the CCC using brain dissection, an analysis of operated cases, and useful measurements for the neurosurgeon.

Re-emergence of rabies virus maintained by canid populations in Paraguay

Paraguay has registered no human cases of rabies since 2004, and the last case in dogs, reported in 2009, was due to a variant maintained in the common vampire bat "Desmodus rotundus". In 2014, a dog was diagnosed as positive for rabies with aggression towards a boy and all required measures of control were successfully adopted. Epidemiological investigation revealed that the dog was not vaccinated and had been attacked by a crab-eating fox, "zorro" (Cerdocyon thous). The sample was diagnosed by the Official Veterinary Service of the Country and sent to the Center on Rabies Research from the University of São Paulo, Brazil, for antigenic and genetic characterization. A second sample from a dog positive for rabies in the same region in 2015 and 11 samples from a rabies outbreak from Asuncion in 1996 were also characterized. The antigenic profile of the samples, AgV2, was compatible with one of the variants maintained by dogs in Latin America. In genetic characterization, the samples segregated in the canine (domestic and wild species)-related group in an independent subgroup that also included samples from Argentina. These results and the epidemiology of the case indicate that even with the control of rabies in domestic animals, the virus can still circulate in wildlife and may be transmitted to domestic animals and humans, demonstrating the importance of continuous and improved surveillance and control of rabies, including in wild species, to prevent outbreaks in controlled areas.

[Microanatomical study of the choroidal fissure in ventricular and cisternal approaches]

The choroidal fissure is a narrow cleft in the medial part of the lateral ventricle, in a C-shaped arc, between the fornix and the thalamus, where the choroidal plexus join. Due to absence nervous tissue between ependyma and pia-mater along this invagination, it is an important route in brain ventricles and cisterns. Five brains were studied by injecting colored silicone arteries and veins and five brains without colored silicone, in a total number of 20 brain hemispheres. It was analyzed and revised the neural, arterial and venous relationships and surgical approaches in all parts of the choroidal fissure. In conclusion, the previous knowledge detailed this microanatomy is primordial for neurosurgeons that will approach brain ventricular and cisternal lesions because the neurosurgeons gain a tridimensional notion that will be indispensable during surgery.