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

Interdisciplinary challenges and aims of flap or graft reconstruction surgery of sinonasal cancers: What radiologists and radiation oncologists need to know

In sinonasal cancer surgery, a fundamental challenge is to understand the postoperative imaging changes after reconstruction. Misinterpretation of post-operative imaging may lead to a misdiagnosis of tumor recurrence. Because radiotherapy planning is based on imaging, there are many gaps in knowledge to be filled in the interpretation of postoperative imaging to properly define radiotherapy tumor volumes in the presence of flaps. On the other hand, radiotherapy may be responsible for tissue fibrosis or atrophy, the anatomy of the reconstructed region and the functional outcomes may change after radiotherapy compared to surgery alone. This narrative review illustrates the interdisciplinary aims and challenges of sinonasal reconstructive surgery using flaps or grafts. It is particularly relevant to radiologists and radiation oncologists, at a time when intensity modulated radiotherapy and proton therapy have the potential to further contribute to reduction of morbidity.

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.

Free Flap Transfer, a Safe and Efficient Method for Reconstruction of Composite Skull Base Defects After Salvage Resection of Advanced Intracranial and Extracranial Communicating Tumors

OBJECTIVE

Surgical treatment of advanced intracranial and extracranial communicating skull base tumors is challenging, especially for the reconstruction of the large composite defect left by tumor resection. The aim of the study is to evaluate the utility of the free flap reconstruction of the defects resulting from radical resection of these tumors in a single institution.

METHODS

The clinical data of 17 consecutive patients who underwent free flap reconstruction for defect left by salvage resection of advanced intracranial and extracranial communicating tumors from 2013 to 2019 were retrospectively collected and analyzed.

RESULTS

There were 5 squamous cell carcinomas, 4 adenoid cystic carcinomas, 2 basal cell carcinomas, 2 meningiomas, 1 anaplastic hemangiopericytoma, 1 pleomorphic adenoma, 1 osteosarcoma, and 1 chondrosarcoma. All patients had recurrent neoplasms, 2 of whom had pulmonary metastasis. A modified radical cervical dissection was performed in 6 patients. The anterolateral thigh myocutaneous flap and rectus abdominis myocutaneous flap were used in 15 patients (88.2%) and 2 patients (11.8%), respectively. Complications were seen in 3 of 17 patients (17.6%) with 1 total flap loss. The median progression-free survival duration was 31 months. The 3- and 5-year progression-free survival rates were 0.47 and 0.24, respectively. The mean overall survival duration was 66 months. The 3- and 5-year overall survival rates were 0.85 and 0.68, respectively.

CONCLUSIONS

Free flap transfer is a safe and effective method with acceptable complications, useful for reconstruction of large composite skull base defects after salvage resection of advanced intracranial and extracranial communicating tumors. The functional and cosmetic results are satisfying.

Are hand biomechanics affected following radial forearm flap harvest? A systematic review and meta-analysis

Donor site morbidity following radial forearm flap (RFF) harvest remains a controversial issue. The aim of this meta-analysis was to answer the question "Are the range of wrist movements (range of motion, ROM) and hand strength affected after RFF harvesting?" The PubMed, Embase, Scopus, and Cochrane Library electronic databases were systematically searched (to December 2019). Self-controlled studies evaluating hand biomechanics after RFF harvest were included. Weighted mean differences with 95% confidence intervals were calculated using the random-effects model. The outcome variables were ROM, forearm movements, grip, and pinch strengths. Thirteen studies involving a total of 335 patients were included. With the exception of grip strength and supination, which showed statistically significant reductions of about 2.40 kg and 2.86° (P <  0.05), all other ROM, forearm movements, and pinch strengths showed an insignificant difference when the operated hand was compared to the non-operated hand (P >  0.05). Regression analysis showed that the method of donor site closure and size of the donor site defect had an insignificant impact on hand biomechanics. This study confirms the lack of discernible biomechanical morbidity after RFF transfer. The minimal reduction in hand biomechanics after RFF is considered to be clinically negligible.

Free tissue reconstruction of the anterior skull base: A review

Objective

There has been a significant shift from open craniofacial resection of the anterior skull base to endoscopic approaches that accomplish the same outcomes in tumor ablation. However, when open resection is required, free flap reconstruction is often necessary to provide sufficient well-vascularized tissue for optimal wound healing as well as providing adequate tissue bulk for cosmesis. This articleaims to providea focused review of free flaps most commonly used in anterior skull base reconstruction.

Methods

This is a state-of-the-art review based on expert opinion and previously published reviews and journal articles, queried using PubMed and Google Scholar.

Results & conclusion

Anterior skull base reconstruction via free tissue transfer is imperative in limiting complications and promoting healing, particularly with large defects, post-radiation, and in at-risk patients. The type of free flap utilized for a particular anterior skull base reconstruction should be tailored to the patient and nature of the disease. This review offers insight into the numerous reconstructive options for the free flap surgeon.

Adipofascial Radial Forearm Free Flap for Anterior Skull Base Reconstruction in Complicated Forebrain Oncological Surgery

BACKGROUND

Radical resections of ethmoidal tumors with intracranial extension present highly complex surgical and reconstructive problems. The purpose of report is to describe the authors' use of adipofascial radial forearm free flaps following unsuccessful anterior cranial fossa oncological surgery.

METHODS

Adipofascial radial forearm free flaps were used to treat 3 similar cases of cutaneous fistula following bone resorption with communication to anterior cranial fossa and nasal cavity.

RESULTS

No flap loss, no deaths, and no postoperative complications were observed. All patients underwent a nasal endoscopy, revealing adequate vitality and integration of the free flaps. One of the patients consented to additional surgery to improve outcome.

CONCLUSIONS

Meticulous preoperative selection and an experienced interdisciplinary team are required to achieve the best surgical outcomes in complex cases. Free adipofascial forearm flaps could be an excellent therapeutic option in the reconstruction of the anterior skull base, notably in cases involving major postoperative complications.

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.