Complications of Open Approaches to the Skull Base in the Endoscopic Era

Complications After Open Skull Base Surgery for Brain Tumors: A 26-Year Experience

INTRODUCTION

Open skull base surgery carries the risk of significant complications. It is important to inform patients and family members clearly of the details of these complications. This study aimed to present the numerous complications encountered with open skull base surgery for brain tumors. This report analyzed the complications experienced by patients treated with open skull base surgery by a single skull base surgeon at a single tertiary center over 26 years.

METHODS

A retrospective study was performed using the University of Puerto Rico Neurosurgery database to identify patients who were managed using open skull base procedures from 1995 to 2020. The neurosurgical database for each patient had been prospectively recorded. Patients with skull base tumors under the author's care during the study period were included in the investigation. Exclusions include patients with non-tumoral conditions and non-skull base tumors and those operated using a microscopic transsphenoidal route. Patients who experienced an intraoperative or postoperative complication within 30 days of the surgery were further analyzed.

RESULTS

In the cohort, 141 patients with brain tumors underwent open skull base surgery. The cohort had a median age of 48 (range 3-79). It consisted of 101 (71.6%) females and 40 (28.4%) males, with a female-to-male ratio of 2.5:1. The approach most frequently used was an orbitofrontal craniotomy (with or without zygomatic osteotomy) in 79 patients (56%). A petrosal approach was utilized in 26 patients (18%). Forty-six patients (33%) developed an intraoperative or postoperative complication. Twenty-four percent of the complications occurred in the 30-day postoperative period. Five patients had more than one complication. The median age of the patients who experienced a complication was 44.5 (range 22-79), with a female-to-male ratio similar to the entire cohort. Cranial nerve injury was the most frequent complication. Worsening or loss of vision in the affected eye occurred in 5.7% of the patients. A cerebrospinal fluid leak occurred in 2% of the patients. Six patients died, two of them after a massive myocardial infarction.

CONCLUSIONS

The results of this study showed that approximately one-third of the patients undergoing open skull base surgery can develop a complication. The most frequent complication was injury to a cranial nerve. A large number of complications occurred intraoperatively. The majority of the complications in patients with tumors in the posterior fossa were associated with injury to a cranial nerve. At the middle fossa, damage to the optic nerves is a noteworthy complication. Complications at the anterior fossa involved worsening of vision or myocardial infarction. Less aggressive surgery near the cavernous sinus and the petroclival region may reduce complications. Understanding the complications can help counsel patients and family members.

Patient-Reported Outcomes in Endoscopic Endonasal Skull Base Surgery

The functional outcome, quality of life, and patient feedback related to a chosen treatment approach in skull base surgery have become a subject of interest and focused research in recent years. The current advances in endoscopic optical imaging technology and surgical precision have radically lowered the perioperative morbidity associated with skull base surgery. This has pushed toward a higher focus on patient-reported outcomes (PROs). It is now critical to ensure that the offered treatment plan and approach align with the patient's preferences and expectations, in addition to the surgeon's best clinical judgment and experience. PROs represent a view that reflects the patient's own thoughts and perspective on their condition and the management options, without input or interpretations from the surgeon. Having PRO data enables patients the opportunity to learn from the experiences and perspectives of other patients. This input empowers the patient to become an active participant in the decision-making process at different stages of their care. An in-depth PRO evaluation requires specific validated tools and scoring systems, namely the patient-reported outcomes measures (PROM) tools. In this review, we discuss the currently available skull-base-related PROs, the assessment tools used to capture them, and the future trends of this important topic that is in its infancy.

Anatomic Considerations of Microvascular Free Tissue Transfer in Endoscopic Endonasal Skull Base Surgery

Objective Though microvascular free tissue transfer is well established for open skull base reconstruction, normative data regarding flap design and inset after endoscopic endonasal skull base surgery (ESBS) is lacking. We aim to describe anatomical considerations of endoscopic endonasal inset of free tissue transfer of transclival (TC) and anterior cranial base resection (ACBR) defects.

Design and Setting Radial forearm free tissue transfer (RFFTT) model.

Participants Six cadaveric specimens.

Main Outcome Measures Pedicle orientation, pedicle length, and recipient vessel intraluminal diameter.

Results TC and ACBR defects averaged 17.2 and 11.7 cm2, respectively. Anterior and lateral maxillotomies and endoscopic medial maxillectomies were prepared as corridors for flap and pedicle passage. Premasseteric space tunnels were created for pedicle tunneling to recipient facial vessels. For TC defects, the RFFTT pedicle was oriented cranially with the flap placed against the clival defect (mean pedicle length 13.1 ± 0.6 cm). For ACBR defects, the RFFTT pedicle was examined in three orientations with respect to anterior–posterior axis of the RFFTT: anteriorly, posteriorly, and laterally. Lateral orientation offered the shortest average pedicle length required for anastomosis in the neck (11.6 ± 1.29 cm), followed by posterior (13.4 ± 0.7cm) and anterior orientations (14.4 ± 1.1cm) (p < 0.00001, analysis of variance).

Conclusions In ACBR reconstruction using RFFTT, our data suggests lateral pedicle orientation shortens the length required to safely anastomose facial vessels and protects the frontal sinus outflow anteriorly while limiting pedicle exposure through a maxillary corridor within the nasal cavity. With greater understanding of anatomical factors related to successful preoperative flap planning, free tissue transfer may be added to the ESBS reconstruction ladder.

Olfaction after endoscopic surgery for sellar and parasellar disease: an updated systematic review and meta-analysis

Background: Whether endoscopic surgery for sellar/parasellar disease causes significant deficits in olfactory function remains unclear. We aimed to systematically review the olfactory outcomes in such settings based on the evidence up to date. Methods: PubMed, EMBASE, and CENTRAL were searched through February 1, 2021. Included studies were limited to endoscopic surgery for sellar/parasellar disease with follow-up olfactory function measured by standardized olfactory testing methods or subjective assessment. The primary outcome was the change in olfactory function after surgery assessed by standardized olfactory testing methods. The secondary outcome was the change in subjective olfactory function. Random-effects model was used in obtaining combine effects. Study quality was assessed using the Newcastle–Ottawa scale. Sensitivity analysis was carried out using the leave-one-out approach, and publication bias was assessed using Egger’s test. Results: The results show no significant difference in olfaction assessed by standardized olfactory testing methods at 1–3 months post-surgery (880 patients in 16 studies) or at 6–12 months post-surgery (1320 patients in 16 studies) compared to pre-surgery, whereas a significantly lower subjective olfaction at 3 months was observed. In addition, the lack of significant change in olfaction as assessed by standardized olfactory testing methods was observed regardless of whether patients were treated with or without the nasoseptal flap (NSF) harvesting. Heterogeneity and publication bias were observed, whereas sensitivity analysis showed the meta-analysis results are robust. Conclusion: The findings of this updated systematic review and meta-analysis support the conclusion that endoscopic surgery for sellar and parasellar pathology may pose no greater risk of olfactory dysfunction. In addition, the current evidence does not support there is an increased risk of diminished olfaction among patients treated with NSF during surgery.

Systematic Review of Olfactory Outcomes After Nasoseptal Flap Harvest for Endoscopic Skull Base Surgery: Does Using Cold Steel or Olfactory Strip Preservation Matter?

BACKGROUND

Several studies have described techniques aimed at mitigating olfactory dysfunction after nasoseptal flap (NSF) harvest for endoscopic skull base surgery (ESBS). No consensus exists as to whether popular methods including using cold-steel (CS) versus electrocautery (EC) or septal olfactory strip (SOS) preservation offer an advantage. This systematic review was performed to examine the impact of these two technical variations of NSF harvest on postoperative olfactory outcomes.

METHODS

Following PRISMA guidelines, Pubmed, Scopus, and Web of Science were searched for articles reporting olfactory outcomes in ESBS cases employing a NSF. Original articles focusing on technique variations of the NSF and reporting at least 1 objective olfactory measure were included.

RESULTS

Nine studies comprising 610 patients were included. Various, olfactory testing outcomes were reported, and post-op follow-up ranged from 6 weeks to 12 months. Three studies, including a randomized-controlled trial, compared the use of CS and EC for the superior incision of the NSF. No significant difference was found in objective olfactory function (p>0.05) when comparing these techniques. Five studies comprising 504 patients reported results from SOS sparing. SOS sparing technique in NSF harvest demonstrated smell preservation in the post-op setting when compared to pre-op measures (p>0.05), however, no direct comparison to non-SOS sparing techniques was made.

CONCLUSION

Use of CS as opposed to EC for the superior NSF incision does not appear to confer an advantage in preserving post-op olfactory function (grade B evidence). SOS preservation may be associated with better olfactory outcomes in NSF harvest (grade C evidence). This article is protected by copyright. All rights reserved.

Predictors of surgical complications in patients with sinonasal malignancy

OBJECTIVES

Sinonasal and skull base tumors are rare, making it difficult to identify trends in surgical outcome. This study examines complications in a large cohort of patients undergoing surgery for sinonasal malignancy.

METHODS

Following IRB approval, an institutional database was reviewed to identify patients who underwent surgery for sinonasal or skull base malignancies from 1973 to 2016 at our institution. Charlson comorbidity index score and Clavien-Dindo grade were calculated. The main study endpoint was subgroup analysis of Clavien-Dindo Grade 0, Grades 1-2, and Grades 3-5 complications. An ordinal logistic regression model was constructed to assess the association between comorbidities, demographics, tumor characteristics, and surgical complications.

RESULTS

In total, 448 patients met inclusion criteria. Perioperative mortality rate at 30 days was 1.6% (n = 7). The rate of severe complications (Clavien-Dindo 3 or higher) was 13.6% (n = 61). Multivariate analysis using an ordinal logistic regression model showed no association between Charlson comorbidity index score and Clavien-Dindo grade of postoperative complication. Advanced T-stage was significantly associated with complications (p = 0.0014; odds ratio: 3.442 [95% confidence interval: 1.615, 7.338]).

CONCLUSION

Surgery for sinonasal and skull base tumors is safe with a low mortality rate. Advanced T-stage is associated with postoperative complications. These findings have implications for preoperative risk stratification. Key Points Surgery for sinonasal malignancy is safe with a 30 mortality of 1.6% and rate of severe complications of 12.8%. There is no association between patient comorbidity and post operative complication. On multivariate analysis, only advanced T stage was associated with increased rate of surgical complication.

The Application of Three-Dimensional Technology Combined With Image Navigation in Nasal Skull Base Surgery

Three-dimensional (3D) technology including 3D reconstruction and 3D printing technology, has been widely used in clinical treatment, especially in surgical planning, and image navigation technology, which can make surgical procedures more accurate, now is also increasingly favored by surgeons. But the combination of those 2 technologies was rarely reported. Thus, this study will preliminarily investigate the feasibility and the effect of the combination of 2 technologies in endonasal skull base surgery. Eight patients were involved in this study (from October 2016 to July 2017 at The Affiliated Hospital of Qingdao University), 5 cases of nasal skull base tumors and 3 cases of foreign body perforation. All operations were done under the assistance of 3D technology and image guidance system. Surgical discussion with patient, preoperative planning and clinical teaching were investigated between 2D images and 3D models by voting. For all cases, 3D reconstruction model and 3D printed model were deemed to be more helpful than CT/MRI images in surgical discussion with the patient; surgical simulation on 3D model in preoperative planning was largely deemed to be helpful and very helpful; and in clinical teaching, 3D models combined with image guidance system were deemed to be more helpful in understanding the disease than using 2D images. Besides, all patients recovered well after surgery, no recurrence and complications were found in the follow-up. The combination of 3D technology and electromagnetic image guidance system could improve surgical efficiency and the quality of clinical teaching.

Averting Delayed Complications of Open Anterior Skull Base Surgery

Objectives Despite its technical feasibility, anterior skull base surgery still carries the risk of severe postoperative complications, morbidity, and mortality. The reported rate of complications has diminished over the past two decades, but they continue to pose various challenges. This study aims to report late complications in a relatively large series of patients who underwent open anterior skull base surgery, and to propose methods for averting such complications.

Methods Retrospective chart review of all patients who underwent anterior open skull base surgery between 2000 and 2016 in a university-affiliated tertiary referral cancer center.

Results There were 301 operations, of which 198 (65.8%) were for benign disease and 103 (34.2%) were for malignant tumors. The male-to-female ratio was 1.4:1, and the mean age was 44.8 years. Delayed complications occurred in 85 patients (28.2%): 31 (10.3%) involved wounds, 18 (13.9%) involved the central nervous system, and 14 (4.6%) involved the orbit. Multivariate analysis found malignant pathology, intracranial extension, and previous radiochemotherapy as predictors for the development of a delayed complication. The patients who were operated in the later study period (after 2007) had lower rates of all three types of complications compared with the earlier study period.

Conclusion Delayed complications following skull base surgery are in decline. This is mainly due to the advancement in imaging studies, surgical techniques, development of sophisticated reconstructive procedures, and the cooperation of multidisciplinary teams. We attribute the reduction in our department to our revised treatment protocol which is presented herein, with emphasis on averting the occurrence of these complications.

Level of Evidence The level of evidence is 4.

Perioperative Considerations in Endoscopic Skull Base Surgery

Purpose of the Review

Present an overview of perioperative considerations specific to endoscopic skull base surgery necessary to maximize successful outcomes.

Recent Findings

The majority of perioperative considerations for endoscopic skull base surgery lack strong supporting evidence and frequently have varied use or implementation amongst institutions. A notable exception comes from a recent randomized controlled trial demonstrating the benefit of lumbar drainage in high-risk cerebrospinal fluid leaks.

Summary

Skull base surgeons must consider a multitude of perioperative factors. While many components of perioperative management are extrapolated from related fields such as endoscopic sinus surgery or open cranial base surgery, additional high-quality studies are needed to delineate best practices specific to endoscopic skull base surgery.

Sinonasal quality-of-life outcomes after endoscopic endonasal skull base surgery

BACKGROUND

There are substantial gaps in our understanding of the influence of the endoscopic endonasal approach (EEA) for endoscopic skull base surgery on sinonasal-specific quality of life (QOL) as well as the instruments available for assessment. Our primary objective in this study was to characterize postoperative changes in sinonasal QOL, specifically using the 22-item Sino-Nasal Outcome Test (SNOT-22), with a secondary objective of delineating weaknesses in our current understanding of patient symptomatology after EEA for skull base surgery.

METHODS

A comprehensive literature review was conducted using PubMed, CINAHL, Cochrane Library, and SCOPUS for studies reporting SNOT-22 data pre- and postoperatively in patients who underwent EEA for skull base pathologies. Studies were limited to patients ≥18 years of age and excluded patients diagnosed with chronic rhinosinusitis (CRS).

RESULTS

Nineteen unique studies with 27 separate data sets and a total of 1025 patients were used in this meta-analysis. Overall SNOT-22 scores statistically improved at the 6-month (p = 0.0009) and 1-year (p = 0.002) time-points. Patients with preoperative SNOT-22 scores ≥20 achieved postoperative improvements at 12-week (p < 0.00001), 6-month (p < 0.0001), 1-year (p < 0.00001), and long-term follow-up (p < 0.0001). Patients with preoperative SNOT-22 scores <20 remained stable and did not worsen postoperatively.

CONCLUSION

Patients undergoing EEA for skull base pathologies who have impaired sinonasal QOL preoperatively demonstrated significant postoperative QOL improvements. Those patients with relatively normal preoperative sinonasal QOL remained asymptomatic postoperatively. This study supports the need for development of a contemporary disease- and approach-specific, validated QOL instrument for skull base pathologies.

Orbitocranial Approaches to the Skull Base

There are a myriad of approaches and surgical options for removal and treatment of skull base diseases. While, historically, large open approaches have been preferred, several endoscopic and minimally invasive techniques are now available that preserve intraoperative visualization and surgical success while minimizing morbidity and recovery times. Herein, the authors review common open, minimally invasive, and endoscopic approaches to the anterior skull base.

Audit of Complications in an Otolaryngology Led Skull-Base Surgical Practice

Objective  This study was aimed to classify and study complications of surgery of the cranial base, primarily from an otorhinolaryngology perspective. Design  This study was designed with consecutive cohort of skull base surgical cases. Setting  Tertiary referral academic center. Participants  Patients having skull-base surgery at a otorhinolaryngology based skull-base unit, from 2002 to 2015. Main Outcome Measures  Enumeration of complications is the main outcome of this study. Surgical procedures, categorized for complexity as per a unified system, are applicable to endoscopic and open procedures. Complications were categorized as per the British Association of Otolaryngologists coding of surgical complications. Complication classified as major if life-threatening, causing permanent disability, or compromising the result of surgery. Results  A total of 342 patients ( n  = 342) were operated; 13 patients' records were excluded due to < 6 months posttreatment follow-up. The study group constituted 204 anterior skull-base (endoscopic, 120; open/external, 84) and 125 lateral skull-base procedures. Complication rates noted to increase in both groups with increasing complexity of surgical intervention. Anterior skull-base surgery (total complications, 11%; major, 3%; death, 0.5%) noted to have significantly less surgical complications than lateral skull-base surgery (total complications, 33%; major, 15%; death, 1.6%; p  < 0.001). Among the anterior procedures no significant difference noted among endoscopic and external approaches when compared across similar surgical complexity. Conclusion  Despite improvement in surgical and perioperative care, the overall major complication rate in a contemporary otolaryngology led, primarily extradural, skull-base practice is noted at 8%. Perioperative mortality, though rare, was encountered in 1%. A standard method for categorization of surgical complexity and the grade of complications as reported here is recommended.

Transfacial and Craniofacial Approaches for Resection of Sinonasal and Ventral Skull Base Malignancies

Malignancies of the paranasal sinuses and ventral skull base present unique challenges to physicians. A transfacial or craniofacial approach allows for wide, possibly en bloc, resection and is ideal for tumors that involve surrounding soft tissue, the palate, the orbit, anterolateral frontal sinus, and lateral dura. Transfacial approaches include a lateral rhinotomy often combined with a medial, subtotal, or total maxillectomy. Reconstruction is most commonly performed with a pericranial flap to separate the intranasal and intracranial compartments. These approaches have evolved and been refined but now are usually reserved for advanced tumors not amenable to endoscopic resection.