Functional Outcomes for Endoscopic and Open Skull Base Surgery: An Evidence-Based Review

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Quality of Life Considerations in Endoscopic Endonasal Management of Anterior Cranial Base Tumors

Considering quality of life (QOL) is critical when discussing treatment options for patients undergoing endoscopic endonasal skull base surgery (EESBS) for cancers at the base of the skull. Several questionnaires have been developed and validated in the last 20 years to explore QOL in this patient population, including the Anterior Skull Base Questionnaire, Skull Base Inventory, EESBS Questionnaire, and the Sino-Nasal Outcome Test for Neurosurgery. The Sino-Nasal Outcomes Test-22 and Anterior Skull Base Nasal Inventory-12 are other tools that have been used to measure sinonasal QOL in anterior cranial base surgery. In addition to pathology-related perturbations in QOL endoscopic surgical options (transsellar approaches, anterior cranial base surgery, and various reconstructive techniques) all have unique morbidities and QOL implications that should be considered. Finally, we look ahead to new and emerging techniques and tools aimed to help preserve and improve QOL for patients with anterior cranial base malignancies.

Endoscopic Endonasal Skull Base Surgery Complication Avoidance: A Contemporary Review

The endoscopic endonasal approach (EEA) provides a direct trajectory to ventral skull base lesions, avoidance of brain retraction, and clear visualization of cranial nerves as they exit skull base foramina. Despite these benefits, the EEA is not without complications. Here, we review published literature highlighting complications associated with the EEA including cerebrospinal fluid (CSF) leak, cranial nerve (CN) dysfunction, pituitary gland dysfunction, internal carotid artery (ICA) injury, infection, and others; we place special emphasis on discussing the prevention of these complications. As widespread adoption of the EEA continues, it becomes critical to educate surgeons regarding potential complications and their prevention while identifying gaps in the current literature to guide future research and advances in clinical care.

Extent of Resection Research in Skull Base Neurosurgery: Previous Studies and Future Directions

Surgery is the first-line therapy for most benign and malignant skull base tumors. Extent of resection (EOR) is a metric commonly used for preoperative surgical planning and to predict risk of postoperative tumor recurrence. Therefore, understanding the evidence on EOR in skull base neurosurgery is essential to providing optimal care for each patient. Several studies from the skull base neurosurgery literature have presented investigations of various topics related to EOR, including 1) preoperative EOR scoring systems, 2) intraoperative EOR scoring systems, 3) EOR and tumor recurrence, and 4) EOR and functional outcomes. We propose that future investigations should focus on the following elements to improve EOR research in skull base neurosurgery: 1) multi-institutional collaboratives with treatment propensity matching; 2) expert consensus and mixed-methods study design; and 3) predictive analytics/machine learning. We believe that these methods offer several advantages that have been described in the literature and that they address limitations of previous studies. The aim of this review was to inform future study design and improve the overall quality of subsequent investigations on EOR in skull base neurosurgery.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Long-Term Sinonasal Function Following Transnasal Pituitary Surgery: A Comparison of Surgical Approach

Background

Surgical approaches to the pituitary have undergone significant changes from transcranial, sublabial, direct transnasal microscopic, and now endoscopic. This study compares sinonasal outcomes from patients from these techniques.

Methods

A cross-sectional study of patients who underwent pituitary surgery in a tertiary setting was conducted. Patients were recruited via phone, mail, e-mail, and in person. Surveys with questions on nasal function, subsequent nasal treatment, the Nasal Symptom Score (NSS), Sinonasal Outcome Test-22 (SNOT-22), Chronic Sinusitis Survey (CSS), and Short Form 36 version 2 (SF-36v2) were obtained.

Results

A total of 252 surveys were sent, of which 165 were returned (65.48% response rate) and 16 were excluded (3 records destroyed, 13 transcranial approach). A total of 149 patients (age 60.10 ± 13.99 years, 47.83% female) were assessed with the following breakdown: sublabial (n = 69), transnasal microscopic (n = 28), and endoscopic (n = 52) approaches. Sublabial and transnasal microscopic, compared to endoscopic, had more sinus treatment (30.43%, 39.29%, and 15.38%; P = .05), medication use (28.99%, 32.14%, and 11.54%; P = .04), and new allergy symptoms (21.74%, 7.14%, and 1.92%; P < .01). Compared to sublabial and transnasal microscopic, endoscopic patients had superior NSSs (0.40 [1.00], 0.60 [1.75], and 0.20 [0.60]; P = .05), SNOT-22 total scores (1.02 ± 0.58, 1.40 ± 0.78, and 1.00 ± 0.59; P < .01), and CSS medication subscores (100.00 [8.33], 100.00 [8.33], and 100.00 [0.00]; P = .03). Endoscopic patients also reported superior SF-36v2 physical subscores (44.02 ± 11.14, 41.13 ± 9.86, and 47.60 ± 10.12; P = .03).

Conclusion

Nasal function was superior, and further sinus therapy and medication use was lower in patients with endoscopic approaches. Disease-specific quality of life was superior and the endoscopic approach resulted in reduced long-term sinonasal morbidity.

Locating and Preserving the Sphenopalatine Ganglion in Endoscopic Endonasal Pterygopalatine Fossa Surgery: An Anatomical Study

Background

The pterygopalatine fossa (PPF) contains numerous important neurovascular structures; notably, the sphenopalatine ganglion (SPG), the maxillary branch of the trigeminal nerve (V2), and the internal maxillary artery. With the advent of extended endoscopic endonasal surgery, the surgical anatomy of the PPF warrants increased investigation. Intraoperative dissection and preservation of the SPG is essential to prevent postoperative xeropthalmia and facial hypoesthesia.

Objective

This study aims to (1) describe a novel dissection technique for identifying the SPG and (2) define the SPG location relative to the sphenopalatine foramen (SPF), which is a consistently identifiable landmark.

Methods

Eight cadaveric PPFs were dissected in step-wise fashion. An endoscopic medial maxillectomy was performed, the SPF was identified, and the posterior maxillary wall was resected. The maxillary branch of the trigeminal nerve (V2) was identified anterolaterally in its infraorbital canal and traced medially to identify the pterygopalatine nerve to the SPG. The lateral distance and superior/inferior distance from the SPG to the fixed SPF was measured.

Results

The surgical technique described allowed for reliable identification of the SPG. The SPG was located on average 4.5 ± 1.1 mm lateral and 1 ± 1.4 mm inferior to the SPF.

Conclusion

Identification and preservation of the SPG is necessary to prevent complications in endoscopic endonasal PPF surgery. The SPG can be reliably located near the SPF by following the pterygopalatine nerve branch of V2.

Survival outcomes for stage-matched endoscopic and open resection of olfactory neuroblastoma

BACKGROUND

Advanced-stage olfactory neuroblastoma requires multimodal therapy for optimal outcomes. Debate exists over endoscopic endonasal surgery in this situation. Stage-matched open and endoscopic surgical therapy were compared.

METHODS

Patients from 6 cancer institutions were assessed. Stratification included dural involvement, Kadish stage, nodal disease, Hyams' grade, approach, and margin status. At follow-up, local control, nodal status, and evidence of distant metastases were recorded with any subsequent therapy. Statistical analyses to identify risk factors for developing recurrence and survival differences were performed.

RESULTS

One hundred nine patients were assessed (age 49.2 ± 13.0 years; 46% women) representing Kadish A stage (10%), Kadish B stage (25%), and Kadish C stage (65%). The majority of the patients (61.5%) underwent endoscopic resection, 53.5% within Kadish C stage. Within-stage survival analysis favored endoscopic subgroup for Kadish C stage (log-rank P = .017) nonsignificant for Kadish B stage (log-rank P = .39).

CONCLUSION

Stage-matched survival was better for the endoscopically treated group compared to the open surgery group, with high negative margin resections obtained.

Endoscopic Resection of Pterygopalatine Fossa and Infratemporal Fossa Malignancies

The endoscopic resection of pterygopalatine and infratemporal fossa malignancies allows excellent visualization and manipulation of tissues in an anatomically complex area compared with open approaches. With less approach morbidity, endoscopic endonasal surgery allows an easier recovery and earlier transition to adjuvant radiotherapy. The endoscopic approach is minimal access but rarely minimally invasive. Surgeons should not hesitate to gain wide surgical exposure of the pterygopalatine, infratemporal fossa, and petrocavernous carotid artery to ensure comfortable maneuverability and easy visualization of the tumor and its normal tissue margins. This method maximizes the chances of complete resection and effective postoperative surveillance.

Quality of life following endoscopic endonasal resection of anterior skull base cancers

OBJECT

For several decades, the exclusive purpose in the management of anterior skull base malignancies has been to increase survival rates. Recently, given the improved prognosis achieved, more attention has been focused on quality of life (QOL) as well. Producing data on QOL in anterior skull base cancers is hampered by the rarity of the neoplasm and the lack of specific questionnaires. The purpose of this study was to assess health-related QOL in a large and homogeneous cohort of patients affected by anterior skull base cancers who had undergone endoscopic endonasal resection.

METHODS

The authors conducted a retrospective review of patients treated for sinonasal and skull base cancers via an endoscopic endonasal approach at two Italian tertiary care referral centers. All patients were asked to complete the Anterior Skull Base Surgery Questionnaire to evaluate their QOL before and 1 month and 1 year after surgical treatment. To assess which parameters affect QOL, the study population was divided into subgroups according to age, sex, stage of disease, surgical approach, and adjuvant therapy.

RESULTS

One hundred fifty-three patients were enrolled in this study according to the adopted inclusion criteria. Overall QOL started at a score of 4.68 for the preoperative period, sharply decreased as far as a score of 4.03 during the 1st postoperative month, and rose again to a score of 4.59 over the course of 1 year after treatment, with a significant difference among the 3 values (p < 0.05). The specific symptoms and physical status domains registered poorer results at the 1-year assessment (4.00 and 4.71, respectively) than at the preoperative assessment (both domains 4.86), with a statistically significant reduction in scores (p < 0.05). Worse outcomes were associated with several variables: age > 60 years (difference of 0.21 points between the preoperative and 1-year period, p < 0.05), expanded surgical approaches with transnasal craniectomy (decrease of 0.20 points between the preoperative and 1-year period, p < 0.05), and postoperative radiotherapy (score of 4.53 at the 1-year period vs. 4.70 in patients without any adjuvant treatment, p < 0.05). No statistically significant differences were found when analyzing the study population according to sex (p > 0.1) and T classification of disease at presentation (p > 0.05).

CONCLUSIONS

Radical endoscopic endonasal resection led to either complete or at least partial recovery of patient QOL within the 1st postoperative year.

Evidence-based practice: endoscopic skull base resection for malignancy

Successful outcomes of endoscopic approaches to benign sinonasal tumors have launched interest in expanding its use for sinonasal malignancy. Because of the heterogeneity and rarity of sinonasal malignancy, evidence for clinical outcomes of endoscopic approaches versus traditional craniofacial resection is low. Using the Oxford Center for Evidence-based Medicine guidelines, we present the existing evidence comparing both techniques for a variety of sinonasal malignancies.