Erratum to ‘Contrast-Enhanced Ultrasonography and Color Doppler: Guided Intraoperative Embolization of Intracranial Highly Vascularized Tumors’ [World Neurosurgery 128 (2019) 547–555]

Combined Use of Color Doppler Ultrasound and Contrast-Enhanced Ultrasound in the Intraoperative Armamentarium for Arteriovenous Malformation Surgery

BACKGROUND

Safety and efficacy in surgical treatment of cerebral arteriovenous malformations (AVMs) are dictated by thorough understanding of angioarchitectural features, intraoperative identification of feeding vessels, and appreciation of surrounding eloquent areas. Our aim was to describe the preliminary results of combined application of color Doppler ultrasound (CDUS) and contrast-enhanced ultrasound (CEUS) in a consecutive surgical series of AVM. We pointed out the tool's efficacy in distinguishing feeding from bystander vessels and in identifying pattern of venous drainage. We examined its role as an adjunct for semiquantitative evaluation of the nidus inflow.

METHODS

We used combined CDUS and CEUS in patients surgically treated for cerebral AVMs. We adopted these techniques following a designed protocol to guide safer AVM resection as an adjunct to indocyanine green videoangiography. Intraoperative assessment by ultrasound was performed before, during, and following nidus resection.

RESULTS

Four surgically treated cerebral AVMs availed of the ultrasound protocol. Postoperative conventional angiography showed complete resection of the AVMs. CDUS and CEUS proved to be valuable adjunctive tools to indocyanine green videoangiography and micro-Doppler in properly navigating and discerning vascular structures, especially vessel feeders from bystanders. The protocol allows us to identify flow direction, estimate blood velocity within the nidus, and appreciate flow modifications following temporary clipping. Ultimately, it allows us to evaluate the degree of nidus deafferentation, residual flow, restoration of venous drainage and absence of arteriovenous shunts.

CONCLUSIONS

The CDUS and CEUS protocol is safe and repeatable and works as real-time imaging, further supporting complete surgical resection of AVMs.

Introducing the High-definition 3D exoscope in ear surgery: preliminary analysis of advantages and limits compared with operative microscope

PURPOSE

The aim of this study was to evaluate the potential of 3D exoscope (EX) in selected ear procedures assessing if this new technology could be an improvement in the field of ear surgery.

METHODS

A case series of consecutive patients surgically treated with a post-auricular approach using EX was retrospectively compared with a similar previous series treated with operating microscope (OM). Patient demographics, indications for surgery, procedure type, complications, operating room setting time (ORst), operative time, adequacy of visualization, image quality, ergonomics aspects, instrument usability, and technique as a teaching tool were investigated. Thirteen patients were included in each group. Surgical procedures in EX group were nine tympanoplasties with mastoidectomy, 1 mastoidectomy for acute complicated mastoiditis, 1 revision miringoplasty, and 2 cochlear implants. Same types of procedures were enrolled in OM group.

RESULTS

No statistically significant difference was found between the two groups concerning ORst and operative time. In EX group, one complication occurred--a middle cranial fossa cerebrospinal fluid leak. Advantages of EX were lightness, maneuverability and compactness, less need of endoscopy during surgery, and teaching potential. Limits were a need of a large surgical corridor and the bright structures rendering in high magnification.

CONCLUSION

EX resulted safe and efficient in treating diseases of the middle ear in post-auricular approaches. To date, EX advantages are not enough to abandon the OM, and it can be considered as an additional, innovative tool to be added to ear surgical equipment.

"Dark corridors" in 5-ALA resection of high-grade gliomas: combining fluorescence-guided surgery and contrast-enhanced ultrasonography to better explore the surgical field

BACKGROUND

Increasing the extent of resection (EOR) is considered a main goal in high grade glioma (HGG) surgery. Significant advancements have been recently made to assist surgery: namely the use of 5-aminolevulinic acid (5ALA) and the application of contrast-enhanced ultrasound (CEUS) embody two of the most recently introduced tools in the neuro-oncology field. A combined approach including the two techniques has been suggested in literature. Our primary aim is to identify in which conditions CEUS final survey has a real impact in a 5-ALA guided context and assess which preoperative tumor characteristics, with specific attention to working corridors can predict strains of the fluorescence guided procedure and hence recommend the use of the combined technique.

METHODS

Forty-nine HGG glioma surgeries were performed at our institution with the abovementioned protocol between January 2016 and June 2016. Based on preoperative MRI, we stratified glioma characteristics according to three determinants: localization (deep versus superficial), size (<3.5 versus >3.5 cm) and shape (regular versus irregular).

RESULTS

CEUS modified 5-ALA guided resection in 11 cases (22.45%): this appeared to be associated with statistically significance to deep tumor localization (P=0.04) and irregular/multi-lobulated margins (P=0.003). On the other hand, tumor size alone did not appear as a statistically significant determinant.

CONCLUSIONS

When dark corridors are presents or when overlying brain parenchyma hinders illumination, drawbacks to the 5-ALA assistance can be expected, hence CEUS final survey has a crucial role of 'refinement'. In those selected cases, an integrated 5ALA+CEUS protocol was shown as advisable in EOR improvement.

Devascularization of a Hemorrhagic Pineocytoma by Laser Thermal Ablation Followed by Endoscopic Resection: A Proof-of-Principle Case Report

BACKGROUND

Thermal coagulation is a central principle in surgery, particularly regarding hemostasis, as well as being an integral part of intracranial tumor removal. Traditionally, surgical hemostasis is achieved through application of unipolar or bipolar electrocautery. This method has been contemporized and specialized to treat intracranial tumors through a technique called stereotactic laser ablation (SLA), also known as laser interstitial thermal therapy.

CASE DESCRIPTION

In this article, we present this technique as an additional option in the treatment of difficult intracranial tumors. Specifically, we report here a highly vascular and hemorrhagic pineocytoma found in a fragile, elderly patient who underwent a novel combination of procedures: SLA mediated devascularization followed by resection via an endoscopic approach.

CONCLUSIONS

SLA-mediated thermal-coagulation is a potential strategy for minimizing hemorrhagic risks in brain tumor resection and may be used in conjunction with other approaches tailored to the patient and their disease.