Clinical and technical factors in endoscopic skull base surgery associated with reconstructive success

BACKGROUND

In this study, we identified key discrete clinical and technical factors that may correlate with primary reconstructive success in endoscopic skull base surgery (ESBS).

METHODS

ESBS cases with intraoperative cerebrospinal fluid (CSF) leaks at four tertiary academic rhinology programs were retrospectively reviewed. Logistic regression identified factors associated with surgical outcomes by defect subsite (anterior cranial fossa [ACF], suprasellar [SS], purely sellar, posterior cranial fossa [PCF]).

RESULTS

Of 706 patients (50.4% female), 61.9% had pituitary adenomas, 73.4% had sellar or SS defects, and 20.5% had high-flow intraoperative CSF leaks. The postoperative CSF leak rate was 7.8%. Larger defect size predicted ACF postoperative leaks; use of rigid reconstruction and older age protected against sellar postoperative leaks; and use of dural sealants compared to fibrin glue protected against PCF postoperative leaks. SS postoperative leaks occurred less frequently with the use of dural onlay. Body-mass index, intraoperative CSF leak flow rate, and the use of lumbar drain were not significantly associated with postoperative CSF leak. Meningitis was associated with larger tumors in ACF defects, nondissolvable nasal packing in SS defects, and high-flow intraoperative leaks in PCF defects. Sinus infections were more common in sellar defects with synthetic grafts and nondissolvable nasal packing.

CONCLUSIONS

Depending on defect subsite, reconstructive success following ESBS may be influenced by factors, such as age, defect size, and the use of rigid reconstruction, dural onlay, and tissue sealants.

Evolution of Radiographic Changes of a Vascularized Pedicled Nasoseptal Flap after Endonasal Endoscopic Skull Base Surgery

BACKGROUND AND PURPOSE

There is active research involving the radiographic appearance of the skull base following reconstruction. The purpose of this study was to describe the radiographic appearance of the vascularized pedicle nasoseptal flap after endoscopic skull base surgery across time.

MATERIALS AND METHODS

We performed chart and imaging review of all patients with intraoperative nasoseptal flap placement during endoscopic skull base surgery at a tertiary academic skull base surgery program between July 2018 and March 2021. All patients underwent immediate and delayed (>3 months) postoperative MR imaging. Primary outcome variables included flap and pedicle enhancement, flap thickness, and flap adherence to the skull base.

RESULTS

Sixty-eight patients were included. Flap (P = .003) enhancement significantly increased with time. Mean nasoseptal flap thickness on immediate and delayed postoperative scans was 3.8 and 3.9 mm, respectively (P = .181). The nasoseptal flap adhered entirely to the skull base in 37 (54.4%) and 67 (98.5%) patients on immediate and delayed imaging, respectively (P < .001).

CONCLUSIONS

Our findings demonstrate heterogeneity of the nasoseptal flap appearance after skull base reconstruction. While it is important for surgeons and radiologists to evaluate variations in flap appearance, the absence of enhancement and lack of adherence to the skull base on immediate postoperative imaging do not appear to predict reconstructive success and healing, with many flaps "self-adjusting" with time.

An endoscopic dural retractor for spinal stenosis surgery

Adequate neural decompression is the goal of lumbar stenosis surgery. Often because of limited visualization of the nerve root, significant portions of the facet joints are removed for decompression enhancing the potential for the development of instability. Clearly, the goal to better visualize the anatomy of the lateral recess while decompressing the nerve root may result in better root decompression and a smaller potential for instability secondary to bone loss. In order to accomplish this goal we have designed an endoscopic dural retractor that while retracting the dura permits simultaneous visualization of the anatomy of the lateral recess and the activity of instruments used to decompress it. The endoscopic dural retractor contains a 10000 pixel endoscope that allows a direct lateral view into the lateral recess while the dura is being retracted. This is a view that cannot be achieved with the operating microscope. One can easily appreciate the anatomy of the lateral recess including the facet joint, ligamentum flavum, lateral dura and nerve root. Ten geriatric cadaver lateral recesses were decompressed endoscopically using the endoscopic retractor. Compression of the nerve root by the facet and ligamentum could easily be identified. One could visually monitor the use of instruments on removal of ligamentum flava and bone compressing the nerve root. In all cases the ligament was easily removed and the facet joint was undercut only enough to decompress the nerve. This instrument has the potential for less invasive decompression of spinal stenosis and further study of its utility is planned.