Bone wax can cause foreign body granuloma in the medulla oblongata

Rational Design of Bioactive Materials for Bone Hemostasis and Defect Repair

Everyday unnatural events such as trauma, accidents, military conflict, disasters, and even medical malpractice create open wounds and massive blood loss, which can be life-threatening. Fractures and large bone defects are among the most common types of injuries. Traditional treatment methods usually involve rapid hemostasis and wound closure, which are convenient and fast but may result in various complications such as nerve injury, deep infection, vascular injury, and deep hematomas. To address these complications, various studies have been conducted on new materials that can be degraded in the body and reduce inflammation and abscesses in the surgical area. This review presents the latest research progress in biomaterials for bone hemostasis and repair. The mechanisms of bone hemostasis and bone healing are first introduced and then principles for rational design of biomaterials are summarized. After providing representative examples of hemostatic biomaterials for bone repair, future challenges and opportunities in the field are proposed.

Methods of Hemostasis in Cranial Neurosurgery: An Anatomy-Based Stepwise Review

BACKGROUND

Hemostasis is crucial in preventing hemorrhage during cranial neurosurgical procedures and maintaining visualization of the surgical field. There is significant variation in the availability of hemostatic methods across different settings and hemostatic techniques are being continuously developed over the decades of practicing neurosurgery. The aim of this article is to provide an outline of the potential methods to achieve hemostasis based on the sequential operative anatomy of a cranial operation.

METHODS

A systematic review was conducted following the PRISMA guidelines. The PubMed database was searched from inception of the database to July 18, 2023. A total of 64 studies were identified fulfilling predefined inclusion criteria, and the risk of bias was assessed using the Joanna Briggs Institute checklists.

RESULTS

Seventy-one hemostatic agents, techniques, tools, and devices were identified, which were then categorized according to the operative phase for which they are indicated. Nine operative anatomic targets were addressed in the sequence in which they are involved during a cranial procedure. For each anatomic target, the following number of hemostatic techniques/agents were identified: 11 for scalp, 3 for periosteum, 10 for skull bone, 11 for dura mater, 9 for venous sinuses, 5 for arteries, 6 for veins, 12 for brain parenchyma, and 4 for cerebral ventricles.

CONCLUSIONS

Depending on the phase of the surgery and the anatomic structure involved, the selection of the appropriate hemostatic method is determined by the source of bleeding. Surgeon awareness of all the potential techniques that can be applied to achieve hemostasis is paramount, especially when faced with operative nuances and difficult-to-control bleeding during cranial neurosurgical procedures.

Recovery after inadvertent intramedullary microchip implantation at C1–C2 in a kitten

Case summary

A 15-week-old male British Shorthair cat was presented for peracute paralysis immediately after microchip implantation. Neurological examination revealed a non-ambulatory tetraparesis and left thoracic limb plegia localised to C1–C5 spinal cord segments. CT of the cervical spine showed a diagonally orientated metallic foreign body (microchip transponder, 10 mm in length) within the vertebral canal at the level of C1–C2, resulting in a penetrating spinal cord injury. Based on concerns about further iatrogenic spinal cord injury through surgery, medical management was chosen. Despite the severe clinical signs, the kitten returned to ambulation within 6 days of the injury, with controlled urination and defecation. Continuous neurological improvement was seen for up to 6 weeks after the injury at which point a mild-to-moderate ambulatory tetraparesis and ataxia remained, with an overall good quality of life. Follow-up CT at the age of 13 months revealed a relative cranial displacement and rotation of the microchip towards the foramen magnum, while the cat’s neurological status was unchanged.

Relevance and novel information

This case demonstrated a cervical penetrating spinal cord injury in a growing cat caused by a microchip, which was successfully managed with medical treatment, suggesting that this might be an option for patients at risk of severe surgery-related complications or where owners reject surgery.

Unusual complications of bone wax at the skull base

OBJECTIVE

This study aimed to describe the clinical presentation, microbiological profile and management of complications of bone wax usage for surgical procedures at the skull base.

METHOD

The case records of a series of five patients who developed post-operative surgical site complications because of bone wax usage during skull base surgery were reviewed.

RESULTS

In all five patients, persistent site-specific clinical features were noted along with intra-operative presence of excessive bone wax. Three unique cases of presentation, one with a fungal brain abscess because of Aspergillus flavus infection, another with fungal osteomyelitis because of Trichosporon beigelii infection and a third with intradural migration of bone wax into the cerebellopontine angle cistern are highlighted.

CONCLUSION

The presentation of surgical site infection at the skull base because of excessive use of bone wax can be manifold. The need for testing appropriate cultures including fungal culture is highlighted.

Intruding implements: a pictorial review of retained surgical foreign objects in neuroradiology

Intra-cranial and spinal foreign body reactions represent potential complications of medical procedures. Their diagnosis may be challenging as they frequently show an insidious clinical presentation and can mimic other life-threatening conditions. Their pathophysiological mechanism is represented by a local inflammatory response due to retained or migrated surgical elements. Cranial interventions may be responsible for the presence of retained foreign objects represented by surgical materials (such as sponges, bone wax, and Teflon). Spinal diagnostic and therapeutic procedures, including myelography, chordotomy, vertebroplasty, and device implantation, are another potential source of foreign bodies. These reactions can also follow material migration or embolization, for example in the case of Lipiodol, Teflon, and cement vertebroplasty. Imaging exams, especially CT and MRI, have a central role in the differential diagnosis of these conditions together with patient history. Neuroradiological findings are dependent on the type of material that has been left in or migrated from the surgical area. Knowledge of these entities is relevant for clinical practice as the correct identification of foreign bodies and related inflammatory reactions, material embolisms, or migrations can be difficult. This pictorial review reports neuroradiological semeiotics and differential diagnosis of foreign body-related imaging abnormalities in the brain and spine.

Sealing of superior semicircular canal dehiscence is associated with improved balance outcomes postoperatively versus plugging of the canal in middle fossa craniotomy repairs: a case series

OBJECTIVE

The authors compared postoperative symptoms between patients with sealed and those with plugged semicircular canal dehiscence repairs.

METHODS

In total, 136 ears from 118 patients who underwent surgical repair for semicircular canal dehiscence were identified via chart review. Data from postoperative MRI scans showing preservation or loss of semicircular canal fluid signal and postoperative reports of autophony, amplification, aural fullness, tinnitus, hyperacusis, hearing loss, vertigo, dizziness, disequilibrium, oscillopsia, and headache were amalgamated and analyzed.

RESULTS

Patients with preservation of fluid signal were far less likely to have dizziness postoperatively (p = 0.007, OR 0.158, 95% CI 0.041-0.611). In addition, these patients were more likely to have tinnitus postoperatively (p = 0.028, OR 3.515, 95% CI 1.145-10.787).

CONCLUSIONS

The authors found that superior semicircular canal dehiscence patients who undergo sealing without plugging have improved balance outcomes but show more tinnitus postoperatively than patients who undergo plugging.

Translation of bone wax and its substitutes: History, clinical status and future directions

Bone wax, primarily composed of beeswax and softening agent, is a century-old material used to control bleeding of disrupted bone surfaces by acting as a mechanical barrier to seal the wound. The current bone wax products are commonly packed in easy-to-open foil in the form of sterile sticks or plates, with excellent malleability and smooth consistency, enabling cost-effective and easy handling approach for bleeding control. It has also been reported that the inert nature of bone wax causes complications including foreign body reaction, infection promotion and bone healing inhibition. With the advances in biomaterials and the market boost of bone haemostatic materials, the arena of bone wax substitute research has expanded to a wide spectrum of material formulations and forms. However, the development of substitutes of bone wax for translation is a pivotal yet challenging topic because currently a potential candidate is recommended to be just as simple to use, effective and inexpensive to produce as traditional bone wax but also be absorbable and osteogenic. This review provides an overview of bone wax including its history, clinical applications and associated complication. In addition, emerging substitutes of bone wax and outlooks of future directions including the standardised evaluation methods are also discussed as an effort to catalyse the innovation and translation of bone haemostatic agents in the near future. The translational potential of this article: Occurrence of osseous haemorrhage is common in surgically incised or traumatically fractured bone. It is essential to stop bone bleeding to avoid further pathologic consequences such as tissue necrosis and eventually mortalities due to blood loss. Medical sterile bone wax is a classical material for haemostasis of bone during orthopaedic surgeries, thoracic surgeries, neurological surgeries and so on. Along with its widespread use, complications such as foreign body reaction, bone healing inhibition and infection promotion associated with bone wax are observed. With the growing knowledge in biomaterials and the boost of market of bone haemostatic materials, bone wax substitute research is thriving. An overview of bone and its substitutes together with evolution of their design criteria is carried out in this work, providing information for the innovation and translation of bone haemostatic agents in the near future.

Foreign Body Granuloma After Cranial Surgery: A Systematic Review of Reported Cases

BACKGROUND

In cranial surgery, different foreign body (FB) materials are used and may be left intentionally or unintentionally in the surgical field after closure, inducing a foreign body granuloma (FBG). This is a rare complication in neurosurgery, but it may be a diagnostic dilemma, with sometimes medicolegal implications.

METHODS

We performed a systematic review of the English literature between 1965 and 2018 and found a total of 77 articles concerning 100 cases of FBG caused by retained material located within the cranium or surrounding soft tissues.

RESULTS

There were 60 females and 40 males, with ages ranging from 1 to 77 years. Most initial diagnoses were cranial/intracranial tumors, trigeminal neuralgia, hemifacial spasm, intracranial aneurysm, hydrocephalus, head injury, infectious disease, and nontraumatic intracerebral hematoma. The interval from the causative surgical operation to presentation of the FBG ranged from 2 weeks to 20 years. Various radiologic modalities were used and histologic study confirmed the presence of FBG in all patients. Intentional FB was used and left in 77 patients, and unintentional FB was found postoperatively in 23 patients. Associated infection was found in 13 patients. Complete recovery was seen in 47.6% of patients with sufficient data.

CONCLUSIONS

Despite being unusual, a retained FBG should be considered in the differential diagnosis of any patient after cranial surgery. A history of surgery, clinical symptoms, physical examination findings, laboratory results, and the use of appropriate neuroimaging explorations may provide a correct preoperative diagnosis. In addition, unintentionally retained FBs are preventable errors in the operating room.

An Unusual Complication of Bone Wax Utilization

Bone wax is a commonly used hemostatic agent with minimal complications. Some of the known complications include inflammation, granuloma formation, infection, and impaired osteogenesis. Several clinical reports of bone wax migration have also been reported. In this paper, the authors present a rare patient of bone wax migration intracranially in a 6-year-old patient who initially underwent craniotomy for the evacuation of subdural hematoma and repair of depressed skull fracture. The patient then underwent craniotomy scalp scar revision several months later. Postoperatively he developed short-term memory loss, apraxia, and word finding difficulties. The imaging findings were consistent with the presence of a foreign body centered in the posterior aspect of the left middle temporal gyrus, which was surgically removed and found to be bone wax. The patient recovered well with complete improvement of his neurologic symptoms.

Migration of Bone Wax into the Sigmoid Sinus after Posterior Fossa Surgery

BACKGROUND AND PURPOSE

Bone wax is a hemostatic agent that has been reported in some instances to migrate into the sigmoid sinus following posterior fossa surgery. The purpose of this study was to characterize the CT and MR imaging findings of this entity.

MATERIALS AND METHODS

The study included 212 consecutive patients who underwent posterior fossa surgery and postoperative CT and contrast-enhanced MR imaging. The presence of sigmoid sinus bone wax migration was determined with the following criteria: sigmoid sinus filling defect showing low signal on all MR imaging pulse sequences; sigmoid sinus filling defect showing low CT attenuation, similar to fat attenuation; and clinical confirmation that bone wax was used intraoperatively. CT and MR imaging of an in vitro bone wax sample was also performed.

RESULTS

We identified 6 cases of sigmoid sinus bone wax migration. In each case, a low-signal-intensity, low-attenuation filling defect was noted in the sigmoid sinus. The morphology was linear (n = 3) or globular (n = 3). In patients with serial imaging, the appearance of migrated bone wax remained stable over time. No adverse outcomes related to sigmoid sinus bone wax migration were encountered. In vitro imaging of bone wax confirmed low CT attenuation and low MR imaging signal intensity on T1WI and T2WI.

CONCLUSIONS

Bone wax migration into the sigmoid sinus is a recognizable imaging finding after posterior fossa surgery that appears to have a benign clinical course. The finding should be distinguished from more serious complications, such as venous sinus thrombosis.

A comprehensive review of topical hemostatic agents: efficacy and recommendations for use

Since ancient times we have attempted to facilitate hemostasis by application of topical agents. In the last decade, the number of different effective hemostatic agents has increased drastically. In order for the modern surgeon to successfully choose the right agent at the right time, it is essential to understand the mechanism of action, efficacy and possible adverse events as they relate to each agent. In this article we provide a comprehensive review of the most commonly used hemostatic agents, subcategorized as physical agents, absorbable agents, biologic agents, and synthetic agents. We also evaluate novel hemostatic dressings and their application in the current era. Furthermore, wholesale acquisition prices for hospitals in the United States are provided to aid in cost analysis. We conclude with an expert opinion on which agent to use under different scenarios.

Mass effect in the thoracic spine from remnant bone wax: an MR imaging pitfall

Bone wax used in neurosurgical procedures is a rare cause of complications after surgery. We present a patient who developed paraplegia following thoracic spine surgery. A subsequent MR imaging study demonstrated a signal void that resembled postoperative air but appeared to cause cord compression and proved after a second surgery to represent bone wax. Recognizing the MR imaging and CT characteristics of bone wax is important to prevent mistaking it for residual air in postoperative imaging.

Infection rates and healing using bone wax and a soluble polymer material

The effects of using a newly available water-soluble polymer bone hemostatic material in a contaminated environment were assessed in a rabbit tibial defect model. Infection rates and healing of polymer-treated bone were compared with the infection and healing of bone wax-treated bone and untreated controls after a bacterial challenge. Defects created in 24 rabbit tibias were treated with the polymer or bone wax, or left without a hemostatic agent. The defects were inoculated with Staphylococcus aureus ATCC-29213 (2.5 x 10(4) colony-forming units). After 4 weeks, all defects treated with bone wax were infected and osteomyelitis had developed, and none had evidence of bone healing. In the polymer and control groups, two defects in each group (25%) had osteomyelitis develop. The remaining six defects in each group (75%) showed no osteomyelitis and exhibited normal bone healing. The polymer-treated defects had a considerably lower rate of osteomyelitis and positive bone cultures compared with the bone wax-treated group. There were no differences between the polymer-treated and control groups in the rates of osteomyelitis, positive cultures, or bone healing. The use of a soluble polymer as an alternative to bone wax may decrease the rates of postoperative bone infections.

Bone wax as a cause of foreign body reaction after lumbar disc surgery: a case report

This report describes a 45-year-old patient who was admitted to the hospital with complaints of low-back pain, lower extremity weakness, and difficulty in walking for the previous 6 mo. The patient's history revealed 2 lumbar-disc surgeries that were performed 1 y earlier. The patient underwent surgery at our hospital because of clinical symptoms and radiologic findings on magnetic resonance imaging. During the operation, 1 x 1 x 1 cm of bone wax that was compressing the dural sac and spinal root was extirpated from the surgical area. Bone wax use should be limited in spinal surgery because of the potential for compression and chronic inflammation.