Contemporary options for lateral skull base reconstruction following tumor extirpation

Primary Dural Repair Using Titanium Microclips Following Lateral Skull Base Surgery

Objective Standard techniques for primary dural repair following lateral skull base surgery are both technically challenging and time consuming without the potential for primary dural repair. Inadequate closure may result in postoperative cerebrospinal fluid (CSF) leak infectious sequalae. Traditional methods of dural repair rely on secondary obliteration of the CSF fistula. We hypothesized that the use of nonpenetrating titanium microclips may serve as a useful adjunct in primary dural repair or the establishment of an immobile repair layer following lateral skull base surgery.

Methods Here, we report a novel technique for primary dural repair using nonpenetrating titanium microclips as an adjunct to standard techniques in a series of six patients with lateral skull base pathologies.

Results A total of six consecutive lateral skull base tumor patients with titanium microclip dural reconstruction were included in our case series. Lateral skull base pathologies represented in this group included two jugular foramen schwannomas, one vestibular schwannoma, one petroclival meningioma, one glomus jugulare paraganglioma, and one jugular foramen chordoid meningioma.

Conclusion To our knowledge, this is the first report on the use of microclips in repairing dural defects following lateral skull base surgery. Surgical outcomes for this small case series suggest that dural repair of the later skull base with nonpenetrating titanium microclips is a useful adjunct in dural repair following lateral skull base surgery.

Characterisation of Selected Materials in Medical Applications

Tissue engineering is an interdisciplinary field of science that has developed very intensively in recent years. The first part of this review describes materials with medical and dental applications from the following groups: metals, polymers, ceramics, and composites. Both positive and negative sides of their application are presented from the point of view of medical application and mechanical properties. A variety of techniques for the manufacture of biomedical components are presented in this review. The main focus of this work is on additive manufacturing and 3D printing, as these modern techniques have been evaluated to be the best methods for the manufacture of medical and dental devices. The second part presents devices for skull bone reconstruction. The materials from which they are made and the possibilities offered by 3D printing in this field are also described. The last part concerns dental transitional implants (scaffolds) for guided bone regeneration, focusing on polylactide–hydroxyapatite nanocomposite due to its unique properties. This section summarises the current knowledge of scaffolds, focusing on the material, mechanical and biological requirements, the effects of these devices on the human body, and their great potential for applications.

The different concepts of surgical managements between anterior and lateral skull base reconstructions based on surgical purposes

OBJECTIVE

Anterior and middle cranial fossa defects require different strategies, depending on their anatomical location. The aim of this study was to elucidate the surgical managements for the defects based on surgical purposes and to clarify the conceptional differences relating to anterior and lateral skull base reconstructions.

METHODS

This study included patients who had undergone reconstructive surgery for anterior or middle cranial fossa defects in our institution between July 2008 and June 2019. It consisted of 66 patients who had been subject to anterior skull base reconstructions, and 84 patients who had experienced lateral skull base reconstructions. The medical records were examined retrospectively, and the surgical purposes and procedures performed were reviewed. The surgical purposes were divided into four groups: Separation, Restoration, Augmentation, and Coverage.

RESULTS

Regarding anterior skull base reconstructions, the Separation group included 65 patients, who represented 98% of this category. There were 26 cases in the Separation-only group, 20 of which were reconstructed with locoregional flaps, and 6 of which with free tissue transfers. A Combination group, which consisted of Separation and Other purposes, consisted of 40 cases. Within this group, 5 cases were reconstructed with locoregional flaps, and 35 with free tissue transfers. Regarding lateral skull base reconstructions, the Separation group included 34 patients, who represented 40% of this category. The rate of the Other purposes represented the majority. In the Separation-only group of 24 patients, 16 cases were reconstructed with locoregional flaps and 8 cases with free tissue transfers. In the Combination group of 10 patients, 2 cases were reconstructed with locoregional flaps and 8 cases with free tissue transfers. In groups other than the Separation group, 27 cases were reconstructed with locoregional flaps and 23 cases with free tissue transfers.

CONCLUSION

In most anterior cranial fossa defect cases, the surgical purpose is separation. In middle cranial fossa defect cases, there are many cases in which the surgical purpose is not separation. In the Separation groups, relating to both anterior and lateral skull base reconstructions, the use of locoregional flaps was an effective measure. Free tissue transfers were required in many cases of the Combination group. Outside of the Separation group associated with lateral skull base reconstructions, the use of locoregional flaps and free tissue transfers were almost equal in proportion, and the selection of reconstructive procedures tended to change from locoregional flaps to large free flaps with increase in the numbers of surgical purposes.

Anterolateral thigh free flap in reconstruction of lateral skull base defects after oncological resection

Purpose

Evaluation of the utility of the free anterolateral thigh flap reconstruction of the defects resulting from radical temporal bone resection in the management of lateral skull base malignancies in a single institution.

Methods

An analysis of 17 en bloc subtotal petrosectomies for removal of malignant tumours was performed. There were 12 squamous cell carcinomas, 4 basal cell carcinomas and 1 adenoid cystic carcinoma. The tumours were staged with the University of Pittsburgh TNM system. In all patients, the lateral temporal bone with the preservation of the petrous apex and carotid artery was performed. All patients had parotid gland resection. The post-resection defect was reconstructed with an ALT free flap.

Results

Tumour radical resection and defect reconstruction with an ALT flap was achieved in all patients without intraoperative complications. The transplants were harvested as fasciocutaneous flaps, 11 perfused by musculocutaneous and 6 by septocutaneous perforators. The ALT flaps had a mean pedicle length of 8 cm (6–12 cm), and the flap size ranged between 6 × 15 cm and 15 × 30 cm. The flaps were supplied by nine facial, five occipital and three maxillary arteries. Recipient-site veins included eight internal jugular, seven facial, one retromandibular and one external jugular vein. All arterial pedicles were anastomosed in an end-to-end manner. The veins were anastomosed with interrupted sutures and in 11 cases with Synovis-Coupler® devices. All the flap transfers were performed successfully. Three patients experienced postoperative complications.

Conclusions

The ALT flap proved to be effective for covering large temporal skull base defects resulting from the radical removal of temporal bone malignancies. The functional and cosmetic results were acceptable with a low complication rate.

Locoregional and Microvascular Free Tissue Reconstruction of the Lateral Skull Base

The goals of reconstruction following any oncologic extirpation are preservation of function, restoration of cosmesis, and avoidance of morbidity. Anatomically, the lateral skull base is complex and conceptually intricate due to its three-dimensional morphology. The temporal bone articulates with five other cranial bones and forms many sutures and foramina through which pass critical neural and vascular structures. Remnant defects following resection of lateral skull base tumors are often not amenable to primary closure. As such, numerous techniques have been described for reconstruction including local rotational muscle flaps, pedicled flaps with skin paddle, or free tissue transfer. In this review, the advantages and disadvantages of each reconstructive method will be discussed as well as their potential complications.

Auricular complications in parotid, temporal bone, infratemporal fossa, and lateral skull base surgery

Neoplasms located in the parotid region, temporal bone, infratemporal fossa, and lateral skull base represent a challenge due to their difficult anatomic location and surrounding neurovascular structures. A variety of surgical approaches are appropriate to access this area, although several of them can place the auricular blood supply in danger. If the auricular blood supply is compromised, ischemia and, eventually, avascular necrosis of the auricle can occur. Auricular necrosis often can cause patients a delay in adjuvant radiation therapy and result in the need for additional reconstructive procedures. Therefore, it is imperative to identify risk factors associated with the development of this disabling complication. We conducted a retrospective review of 32 individuals undergoing treatment of benign and malignant lesions in the parotid gland, infratemporal fossa, and lateral skull base. To identify potential risk factors for auricular necrosis, the patients were analyzed based on the type of neoplasm (malignant or benign), risk factors affecting blood flow (diabetes mellitus, smoking history, prior radiation, prior surgery), body mass index, and the length of surgery. In our population examined, 3 instances of auricular necrosis occurred. None of the potential risk factors proved to be statistically significant (although malignant pathology approached significance at p = 0.07). Two of the patients required an auriculectomy with reconstruction. The third had multiple postoperative clinic visits for surgical debridement. Although no potential risk factors were statistically significant, surgeons should remain cognizant of the auricular blood supply while performing surgery via preauricular and postauricular approaches to this area.

Hydroxyapatite bone cement application for the reconstruction of retrosigmoid craniectomy in the treatment of cranial nerves disorders

BACKGROUND

Retromastoid craniectomy (RSC) is a cardinal surgical approach used to access the posterior fossa. Hydroxyapetite bone cement (HBC) is frequently employed for cranioplasty in efforts to prevent cerebrospinal fluid (CSF) leak, whilst maintaining low complication rates and good cosmetic satisfaction. The authors aim to determine the safety and effectiveness of HBC for reconstruction RSC used for treatment of various cranial nerves disorders.

METHODS

The authors conducted a retrospective one-center two surgeons review of 113 patients who underwent RSC filled with HBC for the treatment of cranial nerve disorders. The study period extended from January 2011 through April 2016. Charts were reviewed for documentation of descriptors pertinent to the endpoints described above. Revisions and reoperations were excluded from analysis.

RESULTS

Ninety-three patients met the inclusion criteria; there was one case of postoperative pseudomeningocele, which was considered as CSF leak (1%), 3 (3,2%) superficial infections, and no deep infections. Cosmetic satisfaction was obtained in all but one case (98.9% satisfaction) and long-term incisional pain was problematic in 1 (1.1%) patient. Other complications (serous drainage, headache, ear pain) accounted for three cases (3.2%).

CONCLUSIONS

The application of HBC in the reconstruction of RSC for the treatment of cranial nerves disorders is an effective method, yielding good cosmetic results whilst eliminating CSF leak. Additionally, it is safe due to the lack of deep-seated wound infections with low incidence of chronic incisional pain.

Surgical treatment of lateral skull base lesions and reconstruction of the skull base: a report of 20 cases

OBJECTIVE

To investigate the surgical treatment and related experience of lateral skull base lesions.

METHODS

In a retrospective, clinical data analysis of 20 patients with lateral skull base diseases, 11 cases with temporal bone space-occupying lesions and intracranial invasion were treated by translabyrinthine surgery, mastoid cavity drainage, or transmastoid surgery to remove the lesion; two cases of cholesteatoma with destruction of tympanic cavity and tympanic sinus canopy with intracranial invasion were treated by extended radical mastoidectomy; seven cases with lateral skull base bone destruction with cerebrospinal fluid otorrhea caused by trauma and deformity were treated by translabyrinth and transmastoid repair.

RESULTS

Eleven cases with temporal bone space occupying lesions were resected completely and were without recurrence after surgery. Two cases with intracranial infection secondary to cholesteatoma were rapidly relieved of symptoms without recurrence after radical mastoidectomy. The remaining seven cases of CSF otorrhea included two cases of Mondini malformation and five cases of temporal bone fracture. The leak was stemmed in all seven cases after surgery.

CONCLUSION

Surgery is the main therapeutic option for the treatment of lateral skull base diseases. The surgical approach and the type of skull base reconstruction should be selected on an individual case-by-case basis.

Fabrication of an Orbital Prosthesis Combined With Eyebrow Transplantation

Fabrication of an orbital prosthesis is considered as a challenging procedure as compared to the other facial prosthesis due to the presence of inactive eye movements and the need of artificial hair in order to mimic eyelashes and eyebrows. Generally these structures are sewed or bonded in the silicone. However, deformation or hair loss is observed within time. This deformation is visible especially in the eyebrow. This clinical report represents a patient with an implant supported orbital prosthesis. Patient was not satisfied with the nature of her eyebrow that was sewed in the silicone. Therefore, an alternative approach of eyebrow transplantation was used for the patient. The patient expressed her better satisfaction of this definitive prosthesis supported with eyebrow transplantation.

Reconstruction of Lateral Skull Base Defects with Radial Forearm Free Flaps: The Double-Layer Technique

Introduction The radial forearm flap has fallen out of favor in lateral skull base reconstruction in recent literature. However, especially when used in a double layer, a radial forearm may be able to provide the thickness of a large flap while taking advantage of the pliability for which the flap is renowned. Objective To report the results of the double-layer technique of radial forearm free flap reconstruction of lateral temporal bone defects. Design A retrospective chart review. Setting A tertiary care institution. Participants All consecutive patients who underwent lateral temporal bone resections and were reconstructed with free flaps from 2006 to 2012. Major Outcome Measures Flap success rate, complications, and rate of revision surgery. Results A total of 17 patients were identified with free flap reconstruction of the lateral skull base. Seven received reconstruction with a double-layer radial forearm flap. Reconstruction-related complications in this group included one case of facial cellulitis. The flap success rate was 100%. These results were comparable with patients who had other flaps. Conclusions The radial forearm free flap may be an effective reconstruction option for lateral temporal bone defects especially when used in the double-layer technique.

Microsurgical anatomy of subtotal temporal bone resection en bloc with the parotid gland and temporomandibular joint

BACKGROUND

Subtotal temporal bone resection (STBR) has been used for half a century to remove temporal bone malignancies. However, there are few reports on the detailed anatomy involved in the resection.

OBJECTIVE

To describe the microsurgical anatomy of STBR combined en bloc with the resection of the parotid gland and temporomandibular joint (TMJ).

METHODS

Cadaveric specimens were dissected in a stepwise manner using 3× to 40× magnification.

RESULTS

STBR can be combined with the total parotidectomy and the resection of the TMJ if the tumor extends into the parotid gland, TMJ, or facial nerve. In this study, we describe the step-by-step microsurgical anatomy of STBR en bloc with the parotid gland and TMJ. The surgical technique described combines 3 approaches: the high cervical, subtemporal-infratemporal fossa, and retromastoid-paracondylar approaches. Combining these 3 approaches aided in efficiently completing this modified approach.

CONCLUSION

STBR is a complicated and technically challenging procedure. This study highlights the importance of understanding the surgical anatomy of STBR and will serve as a catalyst for improvement of the surgical technique for temporal bone resection.