Surgical strategies in the removal of malignant tumors and benign lesions of the anterior skull base

Reconstruction in open anterior skull base surgery: A review and algorithmic approach

PURPOSE

Defects resulting from open resection of anterior skull base neoplasms are difficult to reconstruct. Our objective was to review the literature and describe an evidence-based algorithm that can guide surgeons reconstructing anterior skull base defects.

METHODS

A research librarian designed database search strategies. Two investigators independently reviewed the resulting abstracts and full text articles. Studies on reconstruction after open anterior skull base resection were included. Studies of lateral and posterior skull base reconstruction, endoscopic endonasal surgery, traumatic and congenital reconstruction were excluded. Based on the review, a reconstructive algorithm was proposed.

RESULTS

The search strategy identified 603 unique abstracts. 53 articles were included. Adjacent subsites resected, defect size, radiotherapy history, and contraindications to free tissue transfer were identified as key factors influencing decision making and were used to develop the algorithm. Discussion of the reconstructive ladder as it applies to skull base reconstruction and consideration of patient specific factors are reviewed. Patients with a prior history of radiotherapy or with simultaneous resection of multiple anatomic subsites adjacent to the anterior skull base will likely benefit from free tissue transfer.

CONCLUSIONS

Reconstruction of anterior skull base defects requires knowledge of the available reconstructive techniques and consideration of defect-specific and patient-specific factors.

A Systematic Review on Outcomes of Anterior Skull Base Reconstruction

INTRODUCTION

Anterior skull base resection often results in large defects that need to be reconstructed. This can be done using loco-regional, free flaps or both.

OBJECTIVE

The aim of this systematic review is to evaluate the surgical outcomes (mortality, complication rates and functional outcomes) for patients undergoing anterior skull base reconstruction.

METHODS

Electronic databases (MEDLINE, EMBASE and Scopus) were systematically searched for relevant articles from 1974 to March 2018. A total of 41 studies were included in this systematic review. No randomized controlled trials were identified; therefore, a meta-analysis was not performed.

RESULTS

Mortality from anterior skull base reconstruction were about 0-4% for loco-regional flaps while free flaps were around 0-7%. Overall complications ranged from 0% to 43% in loco-regional flaps, while rate of complications for free flaps ranged from 25% to 66.7%. Flap complications ranged from 0% to 14% for free flaps and 0% to 35% for local flaps. Quality-of-life measures did not differ significantly depending on surgical approach but were worse for patients with malignancies.

CONCLUSION

Due to varying standards of reporting of outcomes, lack of a standardized classification system for anterior skull base defects and absence of clinical trials, we were unable to perform a meta-analysis in this systematic review. Recommendations to guide future studies are proposed.

Anterior skull base reconstruction after tumour resection using the posterior wall of the frontal sinus

INTRODUCTION

The authors describe their experience of surgical closure of the anterior skull base after tumour resection, using the posterior wall of the frontal sinus.

MATERIAL AND METHOD

The authors describe their anterior skull base closure technique performed in three patients after tumour resection. Tumour resection via a transglabellar approach resulted in an anterior skull base defect. Reconstruction consisted of direct implantation of the posterior wall of the frontal sinus without using a bone substitute (except when nasofrontal duct obstruction is required).

RESULTS

Three patients were operated by this surgical procedure with complete tumour resection in every case and no infectious complications. This technique was easy to perform, despite one case of persistent CSF leak. Follow-up imaging showed no displacement of the onlay bone graft.

CONCLUSION

Anterior skull base reconstruction after tumour resection using autologous frontal sinus bone graft is easy to perform with a low complication rate.

Infratemporal fossa approach: the modified zygomatico-transmandibular approach

Background

The infratemporal fossa (ITF) is an anatomical lateral skull base space composed by the zygoma, temporal, and the greater wing of the sphenoid bone. Due to its difficult approach, surgical intervention at the ITF has remained a heavy burden to surgeons. The aim of this article is to review basic skull base approaches and ITF structures and to avoid severe complications based on the accurate surgical knowledge.

Methods

A search of the recent literature using MEDLINE (PubMed), Embase, Cochrane Library, and other online tools was executed using the following keyword combinations: infratemporal fossa, subtemporal fossa, transzygomatic approach, orbitozygomatic approach, transmaxillary approach, facial translocation approach, midface degloving, zygomatico-transmandibular approach, and lateral skull base. Aside from our Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) trial, there have been very few randomized controlled trials. The search data for this review are summarized based on the authors’ diverse clinical experiences.

Results

We divided our results based on representative skull base approaches and the anatomy of the ITF. Basic approaches to the ITF include endoscopic endonasal, transzygomatic, orbitozygomatic, zygomatico-transmandibular, transmaxillary, facial translocation, and the midfacial degloving approach. The borders and inner structures of the ITF (with basic lateral skull base dissection schemes) are summarized, and the modified zygomatico-transmandibular approach (ZTMA) is described in detail.

Conclusions

An anatomical basic knowledge would be required for the appropriate management of the ITF pathology for diverse specialized doctors, including maxillofacial, plastic, and vascular surgeons. The ITF approach, in conjunction with the application of microsurgical techniques and improved perioperative care, has permitted significant advances and successful curative outcomes for patients having malignancy in ITF.

Tailored Extended Bifrontal Craniotomy for Anterior Skull Base Tumors: Anatomic Description of a Modified Surgical Technique and Case Series

BACKGROUND

Open transcranial approaches to the anterior skull base remain an integral component of current skull base practice. Evolution of these and other techniques has resulted in revisions of standard, tried-and-true methods in attempts to improve patient outcomes and cosmesis, while still providing the best combination of surgical exposure and ergonomics.

OBJECTIVE

To describe a modified approach for midline tumors of the anterior skull base.

METHODS

We describe the anatomy and techniques of a modified extended bifrontal craniotomy for anterior skull base tumors. Case examples and a postoperative 3-dimensional computed tomographic reconstruction of the craniotomy are provided.

RESULTS

The technique has been employed with success in 3 tuberculum sellae meningiomas where the anterior limit of the tumor is several centimeters back from the inner table of the frontal bone. The mean distance from the tumor to inner table was 2.8 cm (range 1.3-3.8 cm). Mean tumor dimensions were 3.0 cm (transverse), 3.5 cm (anterior-posterior), and 2.2 cm (craniocaudal). Average operative time was 557 min. No cases had new T2/fluid-attenuated inversion recovery magnetic resonance imaging signal of the inferior frontal lobe to indicate retraction injury.

CONCLUSION

The tailored extended bifrontal craniotomy for anterior skull base tumors provides adequate access to the anterior cranial fossa and has replaced our standard extended bifrontal approach. Keeping the osteotomy cut lines outside of the orbit reduces orbital swelling and mechanical disruption of conjugate eye movements in the early postoperative period, while allowing for minimal frontal lobe retraction and providing sufficient surgical exposure along the anterior skull base.

Minimally invasive surgery of the anterior skull base: transorbital approaches

Minimally invasive approaches are becoming increasingly popular to access the anterior skull base. With interdisciplinary cooperation, in particular endonasal endoscopic approaches have seen an impressive expansion of indications over the past decades. The more recently described transorbital approaches represent minimally invasive alternatives with a differing spectrum of access corridors. The purpose of the present paper is to discuss transorbital approaches to the anterior skull base in the light of the current literature. The transorbital approaches allow excellent exposure of areas that are difficult to reach like the anterior and posterior wall of the frontal sinus; working angles may be more favorable and the paranasal sinus system can be preserved while exposing the skull base. Because of their minimal morbidity and the cosmetically excellent results, the transorbital approaches represent an important addition to established endonasal endoscopic and open approaches to the anterior skull base. Their execution requires an interdisciplinary team approach.

A simple classification of cranial-nasal-orbital communicating tumors that facilitate choice of surgical approaches: analysis of a series of 32 cases

Cranial–nasal–orbital communicating tumors involving the anterior and middle skull base are among the most challenging to treat surgically, with high rates of incomplete resection and surgical complications. Currently, there is no recognized classification of tumors with regard to the choice of surgical approaches. From January 2004 to January 2014, we classified 32 cranial–nasal–orbital communicating tumors treated in our center into three types according to the tumor body location, scope of extension and direction of invasion: lateral (type I), central (type II) and extensive (type III). This classification considerably facilitated the choice of surgical routes and significantly influenced the surgical time and amount of hemorrhage during operation. In addition, we emphasized the use of transnasal endoscopy for large and extensive tumors, individualized treatment strategies drafted by a group of multidisciplinary collaborators, and careful reconstruction of the skull base defects. Our treatment strategies achieved good surgical outcomes, with a high ratio of total resection (87.5 %, 28/32, including 16 cases of benign tumors and 12 cases of malignant tumors) and a low percentage of surgical complications (18.8 %, 6/32). Original symptoms were alleviated in 29 patients. The average KPS score improved from 81.25 % preoperatively to 91.25 % at 3 months after surgery. No serious perioperative complications occurred. During the follow-up of 3 years on average, four patients with malignant tumors died, including three who had subtotal resections. The 3-year survival rate of patients with malignant tumors was 78.6 %, and the overall 3-year survival rate was 87.5 %. Our data indicate that the simple classification method has practical significance in guiding the choice of surgical approaches for cranial–nasal–orbital communicating tumors and may be extended to other types of skull base tumors.

Subcranial craniotomy approach for frontobasal fracture correction

OBJECTIVE

Frontobasilar fracture types and the outcome of patients after management with the subcranial approach technique were evaluated.

MATERIAL AND METHODS

A retrospective analysis of 48 patients (45 males, mean age 38,5 years; range 16-82 years) who had a subcranial approach for frontal base fracture correction between April 1996 and April 2011 at a tertiary care academic hospital in Turku, Finland.

RESULTS

Sixteen (33%) patients had fractures including all frontobasilar fracture types (Type I-IV) i.e. fractures that involved frontal sinuses, orbital roofs, ethmoidal region, cribriform plate and sphenoidal region. Twenty-seven (56%) patients were considered to have had brain damage at presentation. Forty percent of patients were suffering from synchronous trauma. Peroperatively, 31 (65%) patients had exposure or defect of the dura due to bone dehiscence but only two patients suffered from cerebrospinal fluid (CSF) fistula following surgery. CSF fistulae were covered by pericranium in most of the cases (68%). There was no postoperative meningitis. Thirty-eight percent of the patients needed further operation with a subcranial craniotomy following primary reconstruction. At the last follow-up visit 35% were suffering from permanent neurological problems following brain injury.

CONCLUSIONS

Subcranial approach seemed successful in the management of all frontobasilar fractures in this series with reasonably low complication rate. Therefore, we would recommend it as the technique of choice in multiple and even in the most complicated frontal base fractures.

Sinonasal teratocarcinosarcoma involving nasal cavity, nasopharynx, and all paranasal sinuses with bilateral orbital and intracranial extension: A rare case report

Sinonasal teratocarcinosarcoma (SNTCS) is one of the rarest, aggressive malignant neoplasms of sinonasal tract, consisting of primitive neuroepithelial elements with various malignant epithelial and mesenchymal components. Previously described as teratoid carcinosarcoma, malignant teratoma, or blastoma, SNTCS constitutes less than 1% of all cancers and approximately 3% of all malignancies of head and neck region, which is mainly located in the nasal cavity and paranasal sinuses, although tumors occurring in other locations including the nasopharynx and oral cavity have been described. Here, we are presenting a 22-year-old patient with SNTCS involving the nasal cavity, nasopharynx, and all paranasal sinuses with bilateral orbital and intracranial extension treated with surgery followed by radiotherapy and chemotherapy.

Quality of Life following Surgery for Malignancies of the Anterior Skull Base

Radical surgery combined with postoperative radiation is recommended to achieve the best outcomes in patients suffering from malignant anterior skull base tumors. However, information on the impact of such treatment on the quality of life of these patients is sparse. This retrospective study evaluated quality of life in patients with anterior skull base malignancies after transdural resection and radiotherapy. At follow-up, 36% of the patients were alive (mean survival time, 39 months). Only 45% of the patients were able to work in their previous occupation a mean of 15 months after surgery. At follow-up, 58% of the patients had a recurrent tumor. The mean quality of life index was 42 points (range, 0 to 100). The lowest values were on the job item, and the highest mean value was on the family item. All patients, dependents, or both would agree to surgery in the future. Based on these findings, quality of life after transdural surgery for the treatment of anterior skull base malignancies seems to be low.

Combined craniofacial resection of anterior skull base tumors: long-term results and experience of single institution

In this article, the authors are presenting their experience and the results with combined craniofacial resection of anterior skull base tumors based on a review of 27 constitutive cases. Our data are evaluated in comparison to other major centers in other parts of the world, and possible factors that might influence surgical outcome and survival are discussed. Twenty-seven patients diagnosed with anterior skull base tumors between 1999 and 2009 were treated by combined craniofacial resection. Of these patients, there were 19 males (70, 3%) and eight females (29, 7%). The age ranged between 11 and 75 years (mean = 45.9 ± 17.6 years). The follow-up period ranged between 14 and 123 months (avarage = 74 months). The most common presenting symptoms were nasal obstruction and vision disturbance (11 patients for each -40.7%). Total resection was achieved in 24 patients (89%), while subtotal resection was done in three patients (11%). The most common complication was CSF fistule with rhinorrhea, which occurred in five patients (18.5%). Eight patients had recurrences at the time of this long-term follow-up. There were two mortalities in the early postoperative period and seven deaths in the long-term follow-up (overall mortality, 33.3%). The overall 5-year overall survival for all patients in our series was 70.4%. The 5-year overall survival was 62% for patients with malignant tumors and 100% for patients with benign tumors. Combined craniofacial resection of tumors of the anterior skull base is an effective approach for the management of these pathologies. The effectiveness is clearly demonstrated by the clinical results and outcomes of these patients' groups. The favorable prognosis is enhanced by significantly by total resection with negative tumor margins.

A modified frontal-nasal-orbital approach to midline lesions of the anterior cranial fossa and skull base: technical note with case illustrations

The frontal-nasal-orbital craniotomy has been utilized for craniofacial abnormalities and resection of tumors involving the anterior skull base. We describe modifications of this technique to approach extra-axial and intradural midline lesions of the anterior fossa with or without involvement of the skull base. A craniotomy was planned with an endoscope and image guidance. A modified frontal-nasal-orbital craniotomy encompassing the entire frontal sinus complex was performed in conjunction with osteotomies incorporating the bilateral superior orbital ridges and nasal septum. Removal of the posterior wall of the frontal sinus was completed if necessary. Dural repair and final reconstruction are detailed. Our initial experience using this approach in five patients harboring lesions of the anterior skull base resulted in adequate exposure of the targeted pathology. There were no complications of the procedure. Cosmetic results were acceptable. We present a detailed account of this procedure via photographs and a video. The frontal-nasal-orbital craniotomy provides access to the floor of the anterior fossa while avoiding excessive brain retraction associated with facial incisions. In addition, this approach is associated with a lower incidence of complications, such as CSF leak, brain retraction edema, or infection. The frontal-nasal-orbital craniotomy is a useful technique for midline lesions of the anterior skull base, and it should be in the armamentarium of neurological surgeons.

A review of 59 consecutive patients with lesions of the anterior cranial base operated on using the subcranial approach

INTRODUCTION

Lesions of the anterior cranial fossa are still a challenge for the surgeon. Since Joram Raveh introduced the concept of a subcranial approach in 1978 it has been used in the treatment of lesions extending into the anterior cranial fossa. Our experience with the subcranial approach during the past 8 years at Turku University Central Hospital is described.

PATIENTS

Fifty-nine consecutive patients underwent surgery using the subcranial approach for treating various benign and malignant neoplasms, for repair of frontobasal-midfacial fractures, and for repair of cerebrospinal fluid leaks.

METHODS

Patient records were retrospectively reviewed, with special focus on surgical technique, early outcome, and complications.

RESULTS

Nineteen of the patients were operated on because of combined fronto-naso-orbital and skull base fractures, 37 were tumour cases, and 3 patients required surgical repair for cerebrospinal fluid leakage. Significant complications consisted of two cases of meningitis. However, they were successfully treated with antibiotics. The most common late complaint was olfactory nerve dysfunction (44), other late complications such as diplopia (4), enophthalmos (2), scar tissue in the nasal cavity (2), and trigeminal nerve dysfunction (2) were also encountered.

CONCLUSION

The subcranial approach affords exposure to the orbital, sphenoethmoidal, and clivus regions, as well as to the nasal and paranasal cavities. On the basis of this review, it is concluded that it is a safe and effective approach for treating lesions involving the anterior skull base.

Reconstruction après résection tumorale de la base antérieure du crâne par greffon graisseux abdominal

OBJECTIVES

Reconstruction of the anterior skull base is a surgical stage as significant as tumor removal. The quality of the reconstruction is the primary determinant of postoperative mortality, morbidity. The aim of our work was to assess the results of a reconstruction process combining: 1) a pericranium graft held by biological glue to complete the dura mater; 2) an abdominal fat graft supported by a Silastic arch to maintain the neurological structures.

PATIENTS AND METHODS

This was a retrospective study. 55 patients (44 men and 11 women), 59 mean age (14 - 78), were analyzed. 45 had a malignant tumor and 10 a benign tumor. 35 patients were treated using a mixed approach and 18 using a trans frontal-sinus approach alone. Forty-three patients treated for a malignant tumor underwent postoperative radiotherapy. Results were analyzed according to 3 periods: 1) immediate postoperative period (<25 days); 2) early postoperative period (25 days - 3 months); 3) late postoperative period (> 3 months).

RESULTS

None of the patients were lost to follow-up. The average follow up was 84 months. All periods considered together, we had five (9.4%) graft infections, 6 (11.3%) CSF leaks and 1 (1.8%) cases of meningitis.

CONCLUSION

We use a simple technique for reconstruction. Postoperative complications were exceptional, even after postoperative radiotherapy. Medium and long-term results are good and similar to those obtained with other processes used for reconstruction of the anterior skull base reconstruction.