Intraosseous infusion into the skull: potential application for the management of hydrocephalus

Magnetic resonance imaging analysis of human skull diploic venous anatomy

Background:

The skull diploic venous space (DVS) represents a potential route for cerebrospinal fluid (CSF) diversion and absorption in the treatment of hydrocephalus. The goal of this study was to carry out a detailed characterization of the drainage pattern of the DVS of the skull using high-resolution MRI, especially the diploic veins draining to the lacunae laterales (LLs) since the LLs constitute an important channel for the CSF to access the superior sagittal sinus and subsequently the systemic circulation. The objective was to identify those skull regions optimally suited for an intraosseous CSF diversion system.

Methods:

High-resolution, T1-weighted MRI scans from 20 adult and 16 pediatric subjects were selected for analysis. Skulls were divided into four regions, that is, frontal, parietal, temporal, and occipital. On each scan, a trained observer counted all diploic veins in every skull region. Each diploic vein was also followed to determine its final drainage pathway (i.e., dural venous sinus, dural vein, LL, or indeterminate).

Results:

In the adult age group, the frontal and occipital skull regions showed the highest number of diploic veins. However, the highest number of draining diploic veins connecting to the lacunae lateralis was found in the frontal and parietal skull region, just anterior and just posterior to the coronal suture. In the pediatric age group, the parietal skull region, just posterior to the coronal suture, showed the highest overall number of diploic veins and also the highest number of draining diploic veins connecting to the LL.

Conclusion:

This study suggested that diploic venous density across the skull varies with age, with more parietal diploic veins in the pediatric age range, and more occipital and frontal diploic veins in adults. If the DVS is ultimately used for CSF diversion, our anatomical data point to optimal sites for the insertion of specially designed intraosseous infusion devices for the treatment of hydrocephalus. Likely the optimal sites for CSF diversion would be the parietal region just posterior to the coronal suture in children, and in adults, frontal and/or parietal just anterior or just posterior to the coronal suture.

Ossified Occipital Pseudomeningocele following Ventriculoperitoneal Shunt Malfunction

Ossification of pseudomeningocele is a rare occurrence and is one of the rare complications of ventriculoperitoneal (VP) shunt malfunction. We report a case of 12-year-old boy who came with features of raised intracranial pressure following shunt malfunction which was placed as a treatment to the aqueductal stenosis. Computed tomography showed ventriculomegaly and hypodense collection in the occiput with posterior rim of calcification. The findings were confirmed on histopathology. Although ossified pseudomeningocele is a rare entity following VP shunt placement, it should be suspected if patients present with aggravated symptoms, especially if there is shunt malfunction as the treatment option varies with the presence or absence of resultant symptoms and ossification.

Ventriculo-humeral shunt: a cadaveric feasibility study with application to treating hydrocephalus

PURPOSE

Intraosseous vascular access is often used when vascular access is difficult. However, the use of this space for a receptacle for cerebrospinal fluid (CSF) diversion has been scantly considered.

MATERIALS AND METHODS

Six upper limbs of fresh frozen cadavers were used for this study. In the supine position, a small hole was drilled through the outer cortex of the proximal humerus and into the medullary cavity. A 16-gauge needle was placed into the hole in the humerus and 150 cc of saline infused. Next, the adjacent axillary vein and tributaries were dissected to observe dilation or the presence of the blue-colored saline. For part two of the study, shunt tubing was passed subcutaneously from a supraclavicular incision to the hole made in the humerus. Range of motion of the shoulder was then performed.

RESULTS

On all sides, all 150 cc of fluid was easily infused into the humerus. No specimen was found to have leakage from the drill hole site or into the extravascular soft tissues. With dissection of the axillary vein and its tributaries, all sides were found to have engorgement of these vessels. No tension was placed on the distal shunt tubing with full range of motion of the shoulder.

CONCLUSION

Based on our study, the humerus is another option available to the neurosurgeon for CSF diversion.

Intramedullary placement of ventricular shunts: a review of using bone as a distal cerebrospinal absorption site in treating hydrocephalus

PURPOSE

Intraosseous (IO) vascular access has been used since the Second World War and is warranted when there is an emergency and/or urgent need to replenish the vascular pool. Despite long-term and satisfactory results from delivering large quantities of intravenous fluid via the medullary space of bone, use of this space for a distant receptacle for cerebrospinal fluid (CSF) diversion has seldom been considered.

METHODS

The current paper reviews the literature regarding the bony medullary space as a receptacle for intravenous fluid and CSF.

RESULTS

Previous authors have demonstrated the potential of the diploic space of the calvaria for CSF shunting. Pugh and colleagues tested the ability of the cranium to receive and absorb a small amount of tracer fluid.

CONCLUSION

The literature suggests that intraosseous placement of ventricular diversionary shunts is an alternative to more traditional sites such as the pleural cavity and peritoneum. When these latter locations are not available or are contraindicated, placement in the medullary space of bone is another option available to the surgeon.

Intradiploic pseudomeningocele and ossified occipitocervical pseudomeningocele after decompressive surgery for Chiari I malformation: report of two cases and literature review

Intradiploic cerebrospinal fluid (CSF) collections are rare findings. The authors describe two pediatric patients with iatrogenically induced occipital CSF collections after decompressive surgery for Chiari I malformation. The first patient presents a large occipital intradiploic pseudomeningocele and the second patient an intradiploic pseudomeningocele merging with an ossified occipitocervical pseudomeningocele. Though being rarities after decompression for Chiari I malformation, intradiploic fluid collection and ossified pseudomeningocele should be considered if patients represent with aggravating presurgical or new symptoms.

Low-pressure headaches following foramen magnum decompression secondary to absorption of cerebrospinal fluid into the venous system of the diploic space

INTRODUCTION

We describe a case of a patient who suffered low-pressure headaches secondary to absorption of cerebrospinal fluid into the venous system of the diploic space following a foramen magnum decompression. This case is important as it describes a physiologically plausible but previously undescribed complication of a common surgical intervention.

CASE

A nine-year-old boy underwent a foramen magnum decompression for a Chiari malformation (Type I). Five years after his initial decompression, his original symptoms returned and he underwent further decompression with short-term relief of symptoms. He then began to describe low-pressure headaches. Comprehensive investigations revealed a small posterior pseudomeningocoele that had extended into the diploic space at the site of the previous surgery to the occipital bone. It was postulated that the diploic space may be acting as an additional site for reabsorption of his CSF, and as a result of this, he was experiencing consistently low-pressure symptoms. His symptoms have completely resolved following surgical intervention to seal the site of communication with the diploic space.

DISCUSSION

We review recent literature that supports this theory through an understanding of the anatomy of the diploic venous system and also its physiological behaviour as demonstrated in recent cadaveric and porcine studies.

Ventriculosternal Shunting for the Management of Hydrocephalus: Case Report of A Novel Technique

BACKGROUND

Conventional cerebrospinal fluid diversion such as ventriculoperitoneal or ventriculoatrial shunting for the management of hydrocephalus is one of the commonest neurosurgical procedures. However, in selected patients, surgical options are limited when relative contraindications for these operations exist. A patient who underwent ventriculosternal shunting, a novel procedure, is presented with durable and successful outcomes.

OBJECTIVE

To demonstrate the feasibility, durability, and safety of ventriculosternal shunting for the management of hydrocephalus.

METHODS

A patient with end-stage renal failure and heart failure with recurrent pleural effusion suffered from post-subarachnoid hemorrhage communicating hydrocephalus. Because of the need for continuous ambulatory peritoneal dialysis and the risk of introducing excessive cardiac preloading, conventional shunting was relatively contraindicated. Ventriculosternal shunting was performed by adopting the cancellous matrix of the sternum as the anatomic receptacle for intraosseous cerebrospinal fluid absorption. After placement of the ventricular catheter in the usual manner, the distal end was inserted into the sternum.

RESULTS

There was demonstrable clinical and radiological improvement in hydrocephalus by ventriculosternal shunting. Cerebrospinal fluid intraosseous absorption by this novel procedure translated into both physical and cognitive recovery. The procedure was tolerable, effective, and durable, with the patient suffering no complications 3 years after the procedure.

CONCLUSION

Ventriculosternal shunting for the management of hydrocephalus is a feasible, safe, and durable surgical treatment option for selected patients when conventional procedures are contraindicated.

The diploic venous system: surgical anatomy and neurosurgical implications

Object

There are few systematic investigations of the dissected surgical anatomy of the diploic venous system (DVS) in the neuroanatomical literature. The authors describe the DVS relative to different common neurosurgical approaches. Knowledge of this system can help avoid potential sources of unacceptable bleeding and may impact healing of the cranium.

Methods

Using a high-speed drill with a 2-mm bit, the authors removed the outer layer of the compact bone in the skull to expose the DVS in 12 formalin-fixed cadaver heads. Pterional, supraorbital, and modified orbitozygomatic craniotomies were performed to delineate the relationship of the DVS.

Results

The draining point of the frontal diploic vein (FDV) was located near the supraorbital notch. The draining point of the anterior temporal diploic vein (ATDV) was located in all pterional areas; the draining point of the posterior temporal diploic vein (PTDV) was located in all asterional areas. The PTDV was the dominant diploic vessel in all sides. The FDV and ATDV could be damaged during supraorbital, modified orbitozygomatic, and pterional craniotomies. The anterior DVS connected with the sphenoparietal and superior sagittal sinus (SSS). The posterior DVS connected with the transverse and sigmoid sinuses and was the dominant diploic vessel in all 24 sides. Of all the major diploic vessels, the location and pattern of distribution of the FDV were the most constant. The parietal bone contained the most diploic vessels. No diploic veins were found in the area delimited by the temporal squama.

Conclusions

The pterional, orbitozygomatic, and supraorbital approaches place the FDV and ATDV at risk. The major anterior diploic system connects the SSS with the sphenoparietal sinus. The posterior diploic system connects the SSS with the transverse and sigmoid sinuses.