Case report: Side-firing intraoperative ultrasound guided endoscopic endonasal resection of a clival chordoma

Clival chordomas are locally invasive midline skull base tumors arising from remnants of the primitive notochord. Intracranial vasculature and cranial nerve involvement of tumors in the paraclival region necessitates image guidance that provides accurate real-time feedback during resection. Several intraoperative image guidance modalities have been introduced as adjuncts to endoscopic endonasal surgery, including stereotactic neuronavigation, intraoperative ultrasound, intraoperative MRI, and intraoperative CT. Gross total resection of chordomas is associated with a lower recurrence rate; therefore, intraoperative imaging may improve long-term outcomes by enhancing the extent of resection. However, among these options, effectiveness and accessibility vary between institutions. We previously published the first use of an end-firing probe in the resection of a clival chordoma. End-firing probes provide a single field of view, primarily limited to depth estimation. In this case report, we discuss the benefits of employing a novel minimally invasive side-firing ultrasound probe as a cost-effective and time-efficient option to navigate the anatomy of the paraclival region and guide endoscopic endonasal resection of a large complex clival chordoma.

Side-firing intraoperative ultrasound applied to resection of pituitary macroadenomas and giant adenomas: A single-center retrospective case-control study

Introduction

Multiple intraoperative navigation and imaging modalities are currently available as an adjunct to endoscopic transsphenoidal resection of pituitary adenomas, including intraoperative CT and MRI, fluorescence guidance, and neuronavigation. However, these imaging techniques have several limitations, including intraoperative tissue shift, lack of availability in some centers, and the increased cost and time associated with their use. The side-firing intraoperative ultrasound (IOUS) probe is a relatively new technology in endoscopic endonasal surgery that may help overcome these obstacles.

Methods

A retrospective analysis was performed on patients admitted for resection of pituitary adenomas by a single surgeon at the University of Mississippi Medical Center. The control (non-ultrasound) group consisted of twelve (n=12) patients who received surgery without IOUS guidance, and the IOUS group was composed of fifteen (n=15) patients who underwent IOUS-guided surgery. Outcome measures used to assess the side-firing IOUS were the extent of tumor resection, postoperative complications, length of hospital stay (LOS) in days, operative time, and self-reported surgeon confidence in estimating the extent of resection intraoperatively.

Results

Preoperative data analysis showed no significant differences in patient demographics or presenting symptoms between the two groups. Postoperative data revealed no significant difference in the rate of gross total resection between the groups (p = 0.716). Compared to the non-US group, surgeon confidence was significantly higher (p < 0.001), and operative time was significantly lower for the US group in univariate analysis (p = 0.011). Multivariate analysis accounting for tumor size, surgeon confidence, and operative time confirmed these findings. Interestingly, we noted a trend for a lower incidence of postoperative diabetes insipidus in the US group, although this did not quite reach our threshold for statistical significance.

Conclusion

Incorporating IOUS as an aid for endonasal resection of pituitary adenomas provides real-time image guidance that increases surgeon confidence in intraoperative assessment of the extent of resection and decreases operative time without posing additional risk to the patient. Additionally, we identified a trend for reduced diabetes insipidus with IOUS.

Coronavirus Disease 2019 and Pituitary Apoplexy: A Single-Center Case Series and Review of the Literature

Background

Pituitary apoplexy (PA) is a rare, but life-threatening, condition characterized by pituitary infarction and hemorrhage, most often in the setting of a preexisting adenoma. The risk factors and mechanisms associated with PA are poorly understood. Although neurovascular manifestations of coronavirus disease 2019 (COVID-19) infection have been documented, its association with PA has not yet been determined.

Methods

From a prospectively collected database of patients treated at a tertiary care center for pituitary adenoma, we conducted a retrospective medical record review of PA cases during the COVID-19 pandemic from March 2020 to December 2020. We also conducted a literature review to identify other reported cases.

Results

We identified 3 consecutive cases of PA and concomitant COVID-19 infection. The most common symptoms at presentation were headache and vision changes. The included patients were successfully treated with surgical decompression and medical management of the associated endocrinopathy, ultimately experiencing improvement in their visual symptoms at the latest follow-up examination. COVID-19 infection in the perioperative period was corroborated by polymerase chain reaction test results in all the patients.

Conclusions

With the addition of our series to the literature, 10 cases of PA in the setting of COVID-19 infection have been confirmed. The present series was limited in its ability to draw conclusions about the relationship between these 2 entities. However, COVID-19 infection might represent a risk factor for the development of PA. Further studies are required.

Carotid Cavernous Fistulae Occurring After the Use of the Fogarty Catheter in Carotid Surgery

The Fogarty catheter represents a major advancement for the effective removal of distal thrombi during vascular surgery, including carotid endarterectomy (CEA). One complication related to its use is injury to the cavernous carotid artery with development of a carotid cavernous fistula (CCF). Including a recent case at our institution, 21 patients with a Fogarty-related CCF have been reported since 1967. We performed a detailed review of all Fogarty-related CCFs during the treatment of carotid occlusive disease. We suggest a management algorithm for post-CEA acute carotid occlusion.

Transarterial balloon assisted Onyx embolization of pericallosal arteriovenous malformations

SUMMARY

Preliminary experience using a balloon assisted technique (BAT) for embolization of arteriovenous malformations (AVM) is reported. Two patients with large pericallosal AVMs were successfully embolized with Onyx under Scepter C balloon catheter flow arrest.

CLINICAL PRESENTATION

One patient presented with a large intraventricular hemorrhage and hydrocephalus. The second patient presented with a long history of seizures and a small intracerebral hemorrhage. Both patients demonstrated extensive interhemispheric AVMs with multiple arterial feeders, predominantly from the pericallosal arteries.

INTERVENTION

A Marathon microcatheter was navigated into the target arterial feeders and a Scepter C occlusion balloon catheter was inflated immediately proximal. Under flow arrest, Onyx was injected via the microcatheter with excellent nidal penetration. In both cases, there was complete angiographic obliteration of the treated component of the AVM.

CONCLUSIONS

Onyx embolization under balloon catheter flow arrest allows for greater nidal penetration of embolic material and improved reflux control. The technique is limited by the current deliverability of balloon catheters and the potential risk for earlier embolization of dangerous anastomosis.

Direct access to the carotid circulation by cut down for endovascular neuro-interventions

BACKGROUND

Not all vascular lesions of the brain that are amenable to endovascular treatment are safely accessible via the transfemoral route. We describe our technique of carotid cut down for endovascular access and present a couple of illustrative cases. The increasing number of neurosurgeons performing endovascular procedures, or collaborating with interventional neuroradiologists, suggests that this technique should be revived.

METHODS

Through a small transverse neck incision at the level of the thyroid cartilage, the CCA, ICA, and external carotid artery are exposed. After obtaining vascular control with vessel loupes, a purse-string suture is placed in the CCA. Puncture of the artery in the center of the purse string is followed by navigation of a wire, and then a sheath, into the ICA. The neurointervention is then carried out. At the conclusion of the procedure, the sheath is removed from the CCA and the purse string tied to secure the artery.

RESULTS

This technique has allowed us to successfully access the intracranial circulation in 6 patients with challenging anatomy. We present here 2 of the original cases leading to our increasing use of this technique.

CONCLUSION

Carotid cut down for direct puncture of the CCA is a viable option to gain access to the intracranial circulation when the transfemoral route seems difficult or dangerous.

Balloon-assisted coiling through a single 6F guiding catheter

The new version of the 6F Envoy guiding catheter, with its enlarged inner diameter of 0.070 inch, is capable of simultaneously accommodating both a 0.014-inch microcatheter and a balloon microcatheter for balloon-assisted coiling (BAC). We report our experience using this guiding catheter for access in BAC in 48 patients. The guiding catheter allowed for easy manipulations of 2 microcatheters, while providing sufficient quality of control angiograms during the procedure. In cases in which BAC is indicated, a larger guiding catheter (7F) or the commonly used bifemoral approach is no longer necessary, making the procedure technically simpler for the operator and less traumatic to the vessel wall.

Extraventricular cerebral anaplastic ependymomas

BACKGROUND

Anaplastic ependymomas are considered to be uncommon cerebral tumors by most authors. We have had the opportunity to study 34 cases of such lesions in 13 years.

METHODS

34 cases of anaplastic ependymoma operated in different hospitals of Maracaibo, Venezuela, during the period of 1983-1995 were analyzed. Cases of ependymoblastoma were excluded.

RESULTS

Adult patients made up most of the present series. All patients harbored supratentorial growths in locations distant from the ventricular system. The microscopic pattern was of limited value to establish prognosis, for there was no constant correlation between the histologic features and tumor relapse; only in sporadic cases in which high cell density and conspicuous mitotic activity were maximally expressed, did tumor relapse occur shortly after removal of the lesion.

CONCLUSION

This type of paradoxical behavior being the rule makes all attempts at predicting prognosis in these entities a disappointing task.