Management of the cavernous sinus in en bloc resections of malignant skull base tumors

Survey of Skull Base Surgeons' Approach to Carcinomas Involving the Cavernous Sinus

Objectives  Carcinomas involving the cavernous sinus are challenging to resect without compromising important neurovascular structures. Given the morbidity and mortality of these operations, radiotherapy, chemotherapy, and immunotherapy are more often utilized. Although limited to case reports and small series, radical resection of the cavernous sinus has been proposed. We aimed to study surgeons' willingness to perform cavernous sinus exenteration (CSE) under different clinical scenarios. Design, Setting, Participants, Main Outcome Measures  We conducted an online survey from April to July 2021 among members of the Skull Base Congress and the North American Skull Base Society. Descriptive statistics were used to analyze the main outcome measure of willingness to perform CSE . Results  The analytic sample ( n  = 112) included 54% otolaryngologists and 43% neurosurgeons. Eighty-six percent practiced in an academic setting. Surgeons' willingness to perform CSE was low (6-16% under different clinical scenarios), citing a belief that they could not obtain oncologic margins and the procedure's morbidity. Forty-five percent had at least one patient undergo CSE with 72% of patients surviving no more than 2 years. Complications included chronic intractable pain, cerebrospinal fluid leak, cerebrovascular accident, and/or intraoperative/postoperative death within 30 days. Sixty percent agreed that the availability of immunotherapy and genomic sequencing has affected their willingness to offer CSE. Conclusion  Overall, most of the surgeons surveyed were unwilling to offer CSE for carcinomatous cavernous sinus invasion, whether for primary disease or recurrence. Given the rarity of these tumors and the limited data on CSE, these results may provide more information for clinicians and patients for these treatment decisions.

Skull Base Invasion Patterns of Malignant Head and Neck Tumors: A Neurosurgical Perspective

Objective  Craniofacial resection (CFR) and temporal bone resection (TBR) on malignant head and neck tumors (MHNTs) invading skull base require accurate and precise determination of the tumor invasion. We investigated tumor skull base invasion patterns and surgical results in CFR and TBR cases. Methods  We performed either CFR or TBR for 75 selected patients with the possibility of en bloc resection over the period between 2011 and 2018. The medical charts of the selected patients were reviewed. Results  Primary tumor onset site (TOS) groups were: (1) nasal cavity/ethmoid sinus, 20 cases; (2) orbit, 10 cases; (3) maxillary sinus, 28 cases; and (4) external ear/temporomandibular joint, 17 cases. Grades for tumor invasion depth (TID) included: (I) extracranial invasion and skull base bone invasion; (II) extradural invasion; or (III) intradural invasion. Patients in groups 1 and 2 had a significantly higher frequency of grade II and III invasions than patients in groups 3 and 4. The main invasion site was nasal cavity superior wall and ethmoid sinus superior wall for group 1 tumors, orbit superior wall, and lateral skull base sphenoid bone for group 2 and 3 tumors, and lateral skull base temporal bone for group 4 tumors. Positive resection margins represented a significant negative prognostic factor. TID and TOS did not affect skull base margin status. Conclusion  Skull base invasion of MHNTs exhibits certain fixed patterns in sites susceptible to invasion based on the TOS. The frequencies of extradural and intradural invasions differed, indicating the importance for accurate preoperative tumor evaluation.

Role of transcranial sphenoidotomy in skull base surgery: classification of surgical techniques based on the surgical anatomy of the sphenoid sinus

OBJECTIVE

Although sphenoidotomy is more commonly performed via the transnasal approach than via the transcranial approach, transcranial sphenoidotomy (TCS) remains indispensable for en bloc resection of locally advanced sinonasal malignant tumors (SNMTs) extending to the skull base. TCS also enables transsphenoidal transposition of the temporoparietal galeal flap (TPGF) to compensate for the lack of vascularized reconstructive tissue after endoscopic transnasal skull base surgery. The objective of this study was to review the authors' surgical experience using TCS with an emphasis on the surgical anatomy of the sphenoid sinus and on the purpose of TCS. Relevant anatomy is further illustrated through cadaveric dissection and photo documentation.

METHODS

The authors reviewed the records of 50 patients who underwent TCS at the Nagoya University Hospital, Fukushima Medical University Hospital, or Aichi Medical University Hospital over the course of 7 years (between January 2011 and November 2017). The authors also performed cadaveric dissection in 2 adult cadaveric skull base specimens.

RESULTS

Of the 50 patients included in this study, 44 underwent craniofacial resection (CFR) for en bloc resection of SNMTs involving the anterior and/or lateral skull base, and 6 underwent transsphenoidal transposition of the TPGF flap. The authors categorized the TCS procedures according to the portion of the sphenoid sinus wall involved (i.e., superior, lateral, and superolateral). Superior sphenoidotomy was used in patients requiring anterior CFR. Lateral sphenoidotomy was further divided into 2 subtypes, with type 1 procedures performed for the transsphenoidal transpositioning of the TPGF, and type 2 procedures used in patients requiring lateral CFR. Superolateral sphenoidotomy was used in anterolateral CFR.

CONCLUSIONS

TCS still represents a useful tool in the armamentarium of neurosurgeons treating central skull base lesions. The newly proposed surgical classification facilitates a profound understanding of TCS and how to incorporate this technique into clinical practice.

Prospective Evaluation of Health-Related Quality of Life in Patients Undergoing Anterolateral Craniofacial Resection with Orbital Exenteration

Objective  This study was aimed to evaluate health-related quality of life in patients undergoing anterolateral craniofacial resection (AL-CFR) with orbital exenteration (OE) for malignant skull base tumors and to investigate the effects of early psychiatric intervention. Design  Present study is a prospective, observational study. Setting  The study took place at the hospital department. Participants  Twenty-six consecutive patients were selected who underwent AL-CFR with OE at our hospital between 2005 and 2015. Main Outcome Measures  Health-related quality of life was assessed preoperatively and 3, 6, 12, and 24 months after surgery using the Hospital Anxiety and Depression Scale (HADS) and medical outcomes study 8-items Short Form health survey (SF-8). In all cases, psychiatric intervention was organized by the consultation liaison psychiatry team preoperatively and postoperatively. Results  Ten (38.0%) of the 26 patients died and 16 (62.0%) were alive and disease-free at the end of the study. The 3-year overall and disease-free survival rates were 64.9% and 53.3%, respectively. Twenty-one patients (80.8%) developed psychiatric complications after surgery and needed treatment with psychotropic medication. Before surgery, 28% of patients had HADS scores ≥8 for anxiety and 20% had scores ≥8 for depression. Seven of the eight items in the SF-8 were significantly lower than those for the general Japanese population. However, scores for all the SF-8 items gradually improved during postoperative follow-up, reaching approximately 50 points, which is the national standard value, at 2 years after surgery. Conclusions  Craniofacial resection with OE was feasible and well tolerated in patients with malignant skull base tumors who received early psychiatric intervention to decrease the considerable psychological impact of this procedure.

Preoperative surgical simulation and validation of the line of resection in anterolateral craniofacial resection of advanced sinonasal sinus carcinoma

BACKGROUND

The purpose of this study was to assess the usefulness and accuracy of preoperative 3D virtual simulation of anterolateral craniofacial resection in cases of advanced sinonasal sinus carcinoma.

METHODS

Seven patients with advanced (T4 classification) sinonasal sinus carcinoma who underwent anterolateral craniofacial resection in our hospital between 2011 and 2013 were included in this study. Postsimulation CT images were fused with postoperative CT images and differences between the planned and actual osteotomy were measured in 3 regions of the skull base.

RESULTS

The differences ranged from 0 mm to 5.8 mm (average, 3.1 mm) at the inferior wall of the cavernous sinus, from 0.8 mm to 8.3 mm (average, 3.5 mm) at the inferior wall of the sphenoid sinus, and from 0 mm to 13.6 mm (average, 2.3 mm) in the palatine bone.

CONCLUSION

Preoperative 3D virtual surgical simulation and postoperative feedback can contribute to training for surgeons. © 2016 Wiley Periodicals, Inc. Head Neck 39: 512-519, 2017.

En bloc petrosectomy for malignant tumors involving the external auditory canal and middle ear: surgical methods and long-term outcome

OBJECTIVES

The aim of this study was to describe a method for resecting malignant tumors originating in the external auditory canal or middle ear and requiring en bloc resection of the petrous bone.

METHODS

Between 1995 and 2005, the authors performed en bloc petrosectomy for 18 malignant tumors in 9 male and 9 female patients, ranging in age from 15 to 74 years. Fourteen tumors originated in the external ear, 2 in the middle ear, and 2 in the parotid gland. The pathological entities included 15 squamous cell carcinomas, 2 adenoid cystic carcinomas, and 1 rhabdomyosarcoma. Through an L-shaped temporosuboccipital craniotomy, a medial osteotomy was created through the inner ear for tumors without extension into the inner ear (14 cases) and through the tip of the petrous bone for tumors reaching the inner ear (4 cases). Temporal dura mater in 3 patients and the base of the temporal lobe in 2 patients were included in the en bloc resection.

RESULTS

Surgical complications occurred in 5 patients (28%) with no deaths. During a mean follow-up period of 45 months, 3 patients died of tumor recurrence. Overall, 2- and 5-year survival rates were 86 and 78%, respectively. Two of three patients with dural extension and 1 of 2 with brain invasion remain alive. Two of four patients with tumor extension into the inner ear died.

CONCLUSIONS

En bloc petrosectomy is recommended for malignant tumors of the ear. It is safe and effective for lesions limited to the middle ear and may be the procedure of choice for tumors reaching the inner ear and those with dural or brain invasion.

Evaluation of the healing process after dural reconstruction achieved using a free fascial graft

OBJECT

This study was undertaken to investigate the healing process and to delineate factors important for the survival of free fascial grafts used for dural repair.

METHODS

A dural defect was created in guinea pigs and then reconstructed using either a free fascial graft or an expanded polytetrafluoroethylene (ePTFE) sheet. The fascial graft was covered directly by subcutaneous tissue (Group I) or by a silicone sheet to prevent tissue ingrowth from the subcutaneous tissue (Group II). The ePTFE sheet was covered with a silicone sheet (Group III). One or 2 weeks postoperatively, the strength of the dural repair was evaluated by determining the pressure at which cerebrospinal fluid (CSF) leaked through the wound margins. The dural repair was also histologically examined. In addition, using a rat model, specimens obtained from similar reconstruction sites were immunohistochemically stained with antibodies against basic fibroblast growth factor (bFGF), epidermal growth factor, or transforming growth factor-beta. The pressures at which CSF leaked after 1 and 2 weeks, respectively, were 50 +/- 14 mm Hg and 126 +/- 20 mm Hg in Group I, 70 +/- 16 mm Hg and 101 +/- 38 mm Hg in Group II, and 0 mm Hg and 8 +/- 8 mm Hg in Group III. Failure of repairs made in Group III occurred at significantly lower pressures when compared with Groups I and II. In Groups I and II, a thick fibrous tissue formed around the fascial graft. This tissue tightly adhered to adjacent dura mater. The fibrous tissue displayed a positive reaction for the presence of bFGF. In Group III, only a thin fibrous membrane surrounded the ePTFE sheet.

CONCLUSIONS

Fascial grafts tolerated extraordinary intracranial pressures at 1 week postoperatively. Free fascial grafts can heal with durable fibrous tissue without the presence of a blood supply from an overlying vascularized flap.