Impact of Dynamic Endoscopy and Bimanual-Binarial Dissection in Endoscopic Endonasal Surgery Training: A Laboratory Investigation

Effect of the extent of posterior septectomy on surgical access during the endoscopic endonasal approach to the sella: A technical note

Background

Using the bi-nostril 4-hand technique during the endoscopic endonasal approach (EEA) facilitates bimanual microsurgical techniques yet requires resection of the posterior nasal septum. The surgical exposure and degree of maneuverability gained proportionate to the extent of posterior septectomy in the sagittal plane was previously quantified.

Research question

We aim to describe our technique of posterior septectomy, and the effect of its extent in the axial plane on surgical access, and instrument maneuverability.

Material and methods

After fracturing the posterosuperior nasal septum, we disarticulate the vomer from the sphenoid rostrum and remove its upper part. The sphenoid rostrum is excised next exposing the clival recess where a suction tip without a side channel is anchored, allowing the assisting surgeon to use an additional instrument in their dominant hand. The vomer is removed down to the level of the floor of the sphenoid sinus.

Results

A wide exposure is achieved in the coronal plane bilaterally at the level of the sphenoid rostrum allowing unobstructed instrument manipulation in the craniocaudal and cross-court trajectories. Furthermore, the floor of the sella is reached through a straight rather than angled trajectory facilitating surgical access, manipulation, and instrument maneuverability. For lateral lesions requiring contralateral access, the assisting surgeon can assist in dissection from the contralateral nostril without changing the position of the endoscope.

Discussion and conclusion

Removing the upper vomer improves surgical access, and instrument maneuverability. Simultaneous dissection from both nostrils might be attempted. Caudally extending the posterior septectomy during the EEA allows better exposure and improves surgical access in all planes.

Fascia Lata: Another Workhorse for Complex Skull Base Reconstruction

BACKGROUND

Multiple methods exist for skull base reconstruction of defects created by expanded endonasal approaches. While the nasoseptal flap (NSF) has been well established as the workhorse of mucosal reconstruction in complex skull base defects in multi-layered closures, a variety of options exist for the inner layer of multilayer reconstruction, including fascia lata (FL).

OBJECTIVE

To present our experience and outcomes in utilizing FL in multiple ways to reconstruct a wide variety of complex skull base defects.

METHODS

Retrospective review was performed from May 2017 to February 2022 to identify 50 consecutive patients who underwent endoscopic skull base reconstruction using FL.

RESULTS

FL was employed for reconstruction in 50 patients included in the study: 37 undergoing primary expanded endonasal skull base surgery and 13 revision cases. A wide range of complex pathology was treated, with meningioma and craniopharyngioma being the two most common. FL was utilized as a "button" graft (34/50, 68.0%), free graft inlay/onlay (13/50, 26.0%), and as a button graft combined with onlay (3/50, 6.0%). Expanded surgery defects addressed included tuberculum sella/sphenoid planum (36/50, 72.0%), clivus (6/50, 12.0%), and cribriform/planum (8/50, 16.0%). Successful reconstruction with fascia lata was accomplished in 46/50 cases (92%), with only 4 cases (8%) requiring revision for post-op CSF leak. Donor-site complications were rare with only 1 case (2.0%) of post-op seroma.

CONCLUSION

FL, usually with NSF, offers a versatile option for the reconstruction of challenging defects with excellent outcomes and minimal morbidity. FL is emerging as a workhorse for reconstruction of the inner layer of complex skull base defects.

A Novel Low-Cost Exoscopy Station for Training Neurosurgeons and Neurosurgery Trainees

BACKGROUND

The loss of stereopsis and the need for markedly enhanced hand-eye coordination are obstacles to overcome when performing exoscopic procedures, but both should improve with training. Our objectives were to describe an exoscopy training station and to compare time and performance of a given microsurgical technique among neurosurgery residents and junior neurosurgeons.

METHODS

We designed a low-cost exoscopy training station featuring a notebook computer, a webcam, and a light-emitting diode source. Surgeons and surgical trainees with no experience in exoscopy were enrolled and divided into 2 groups (trainees and controls). Performance and time in suture placement were evaluated by a skilled observer in both groups at baseline and 3 days later. Between evaluations, trainees completed an exoscopy training module.

RESULTS

There were 22 participants divided equally into 2 groups. At baseline, trainees had a greater percentage of proper sutures than controls (58% vs. 35%), but they were also slower (32 minutes vs. 25 minutes). On final evaluation, not only were trainees approximately 14 minutes faster than at baseline (P = 0,03), but also their successful suture rate had increased by 18% (final rate 76%, P = 0.02). Moreover, controls were faster compared with baseline by 6 minutes (P = 0.003), but their percentage of successful sutures did not increase (final rate 38%, P = 0.49). The change from baseline to final evaluation favored trainees for both outcomes (P = 0.03 and P = 0.02).

CONCLUSIONS

Using the exoscopy training station, the trainees were able to improve their time and performance of exoscopy compared with the controls.

Ergonomics of Endoscopic Skull Base Surgery: A Systematic Review

OBJECTIVE

There has been a significant expansion in endonasal endoscopic skull base surgery (EES) that has been used to address a wide range of intracranial and sinonasal pathologies. Although there exists a large amount of literature on approaches and patient outcomes, there is a paucity of data describing ergonomics in this field. Our goal was to evaluate and summarize the literature on ergonomics in EES.

METHODS

We systematically reviewed all published, peer-reviewed, English language literature in the PubMed and Web of Science databases as screened by multiple reviewers describing ergonomics as related to EES.

RESULTS

A total of 50 articles were found that described significant conclusions and descriptions on ergonomics in EES. We found and summarized the different technical aspects of ergonomics as pertaining to EES and provided evidence-based suggestions on operating room and surgeon setup.

CONCLUSIONS

There are several improvements in EES ergonomics that can decrease fatigue, improve efficiency, and overall surgeon well-being.