Skull base reconstruction in the pediatric patient

Surgical treatment of pediatric rhabdomyosarcoma in the parameningeal-nonparameningeal region

OBJECTIVES

Rhabdomyosarcoma (RMS) involving the parameningeal-nonparameningeal region (PNP) is relatively rare in pediatric patients (PPs). The current study aimed to report the outcomes of RMS-PNP-PPs who received surgical resection combined with concurrent flap reconstruction.

METHODS

A retrospective study was conducted concerning RMS-PNP-PPs who received combined skull-maxillofacial resection with flap reconstruction during the period from 2012 to 2016. Predictive factors for recurrence-free survival (RFS), metastasis-free survival (MFS), and overall survival (OS) were preliminarily identified by Kaplan-Meier analysis.

RESULTS

A total of 16 RMS-PNP-PPs were finally enrolled; recurrence, metastasis and death were found in 7, 7 and 5 patients, respectively. Following surgical ablation involving the skull base and maxillofacial region, reconstruction was performed with a local flap in 9 patients, a latissimus dorsi flap in 3 patients, and an anterolateral thigh flap in 4 patients. Through univariate analysis, we demonstrated that the primary site + surgical margins, postoperative RT/CT + Ki-67/Bcl-2 IHC, and surgical margins + Ki-67/Bcl-2 IHC could be used as the preliminarily prognostic factors for RFS, MFS and OS, respectively.

CONCLUSIONS

RMS-PNP-PPs showed poor prognosis even when surgical resection combined with flap reconstructions was performed. Achieving a clear surgical margin and good conduction of postoperative RT/CT should be taken into consideration to acquiring a better surgical outcome.

Medical information security in the era of artificial intelligence

In recent years, biometric technologies, such as iris, facial, and finger vein recognition, have reached consumers and are being increasingly applied. However, it remains unknown whether these highly specific biometric technologies are as safe as declared by their manufacturers. As three-dimensional (3D) reconstruction based on medical imaging and 3D printing are being developed, these biometric technologies may face severe challenges.

Extended middle fossa approach to lateralized pontine cavernomas in children

OBJECTIVE Treatment of hemorrhagic cavernous malformations within the lateral pontine region demands meticulous surgical planning and execution to maximize resection while minimizing morbidity. The authors report a single institution's experience using the extended middle fossa rhomboid approach for the safe resection of hemorrhagic cavernomas involving the lateral pons. METHODS A retrospective chart review was performed to identify and review the surgical outcomes of patients who underwent an extended middle fossa rhomboid approach for the resection of hemorrhagic cavernomas involving the lateral pons during a 10-year period at Rady Children's Hospital of San Diego. Surgical landmarks for this extradural approach were based on the Fukushima dual-fan model, which defines the rhomboid based on the following anatomical structures: 1) the junction of the greater superficial petrosal nerve (GSPN) and mandibular branch of the trigeminal nerve; 2) the lateral edge of the porus trigeminus; 3) the intersection of the petrous ridge and arcuate eminence; and 4) the intersection of the GSPN, geniculate ganglion, and arcuate eminence. The boundaries of maximal bony removal for this approach are the clivus inferiorly below the inferior petrosal sinus; unroofing of the internal auditory canal posteriorly; skeletonizing the geniculate ganglion, GSPN, and internal carotid artery laterally; and drilling under the Gasserian ganglion anteriorly. This extradural petrosectomy allowed for an approach to all lesions from an area posterolateral to the basilar artery near its junction with cranial nerve (CN) VI, superior to the anterior inferior cerebellar artery and lateral to the origin of CN V. Retraction of the mandibular branch of the trigeminal nerve during this approach allowed avoidance of the region involving CN IV and the superior cerebellar artery. RESULTS Eight pediatric patients (4 girls and 4 boys, mean age of 13.2 ± 4.6 years) with hemorrhagic cavernomas involving the lateral pons and extension to the pial surface were treated using the surgical approach described above. Seven cavernomas were completely resected. In the eighth patient, a second peripheral lesion was not resected with the primary lesion. One patient had a transient CN VI palsy, and 2 patients had transient trigeminal hypesthesia/dysesthesia. One patient experienced a CSF leak that was successfully treated by oversewing the wound. CONCLUSIONS The extended middle fossa approach can be used for resection of lateral pontine hemorrhagic cavernomas with minimal morbidity in the pediatric population.

Surgical Interventions for Advanced Parameningeal Rhabdomyosarcoma of Children and Adolescents

Owing to its rarity, rhabdomyosarcoma of the head and neck (HNRMS) has seldom been discussed in the literature. As most of the data is based only on the retrospective experiences of tertiary healthcare centers, there are difficulties in formulating a standard treatment protocol. Moreover, the disease is poorly understood at its pathological, genetic, and molecular levels. For instance, 20% of all histological assessment is inaccurate; even an experienced pathologist can confuse rhabdomyosarcoma (RMS) with neuroblastoma, Ewing’s sarcoma, and lymphoma. RMS can occur sporadically or in association with genetic syndromes associated with predisposition to other cancers such as Li-Fraumeni syndrome and neurofibromatosis type 1 (von Recklinghausen disease). Such associations have a potential role in future gene therapies but are yet to be fully confirmed. Currently, chemotherapies are ineffective in advanced or metastatic disease and there is lack of targeted chemotherapy or biological therapy against RMS. Also, reported uses of chemotherapy for RMS have not produced reasonable responses in all cases. Despite numerous molecular and biological studies during the past three decades, the chemotherapeutic regimen remains unchanged. This vincristine, actinomycin, cyclophosphamide (VAC) regime, described in Kilman, et al. (1973) and Koop, et al. (1963), has achieved limited success in controlling the progression of RMS. Thus, the pathogenesis of RMS remains poorly understood despite extensive modern trials and more than 30 years of studies exploring the chemotherapeutic options. This suggests a need to explore surgical options for managing the disease. Surgery is the single most critical therapy for pediatric HNRMS. However, very few studies have explored the surgical management of pediatric HNRMS and there is no standard surgical protocol. The aim of this review is to explore and address such issues in the hope of maximizing the number of options available for young patients with HNRMS.

Skull Base Reconstruction in the Pediatric Patient

Introduction  Pediatric skull base and craniofacial reconstruction presents a unique challenge since the potential benefits of therapy must be balanced against the cumulative impact of multimodality treatment on craniofacial growth, donor-site morbidity, and the potential for serious psychosocial issues. Objectives  To suggest an algorithm for skull base reconstruction in children and adolescents after tumor resection. Materials and Methods  Comprehensive literature review and summary of our experience. Results  We advocate soft-tissue reconstruction as the primary technique, reserving bony flaps for definitive procedures in survivors who have reached skeletal maturity. Free soft-tissue transfer in microvascular technique is the mainstay for reconstruction of large, three-dimensional defects, involving more than one anatomic region of the skull base, as well as defects involving an irradiated field. However, to reduce total operative time, intraoperative blood loss, postoperative hospital stay, and donor-site morbidity, locoregional flaps are better be considered the flap of first choice for skull base reconstruction in children and adolescents, as long as the flap is large enough to cover the defect. Our "workhorse" for dural reconstruction is the double-layer fascia lata. Advances in endoscopic surgery, image guidance, alloplastic grafts, and biomaterials have increased the armamentarium for reconstruction of small and mid-sized defects. Conclusions  Skull base reconstruction using locoregional flaps or free flaps may be safely performed in pediatrics. Although the general principles of skull base reconstruction are applicable to nearly all patients, the unique demands of skull base surgery in pediatrics merit special attention. Multidisciplinary care in experienced centers is of utmost importance.

Utilization of a submental island flap and 3D printed model for skull base reconstruction: Infantile giant cranio-cervicofacial teratoma

Transcranial masses in the infant population can leave considerable skull base defects following resection. Traditional reconstructive techniques can result in significant morbidity or poor cosmetic results. We present a case of a large skull base defect in a six week-old infant, after removal of a giant cranio-cervicofacial teratoma, which was reconstructed using a versatile submental island flap. Additionally, preoperative planning and intraoperative navigation was advanced with the use of a 3D constructed model of the patient's mass.

Single-staged resections and 3D reconstructions of the nasion, glabella, medial orbital wall, and frontal sinus and bone: Long-term outcome and review of the literature

BACKGROUND

Aesthetic facial appearance following neurosurgical ablation of frontal fossa tumors is a primary concern for patients and neurosurgeons alike. Craniofacial reconstruction procedures have drastically evolved since the development of three-dimensional computed tomography imaging and computer-assisted programming. Traditionally, two-stage approaches for resection and reconstruction were used; however, these two-stage approaches have many complications including cerebrospinal fluid leaks, necrosis, and pneumocephalus.

CASE DESCRIPTION

We present two successful cases of single-stage osteoma resection and craniofacial reconstruction in a 26-year-old female and 65-year-old male. The biopolymer implants were preselected and contoured based on imaging prior to surgery. The ideal selection of appropriate flaps for reconstruction was imperative. The flaps were well vascularized and included a pedicle for easy translocation. Using a titanium mesh biopolymer implant for reconstruction in conjunction with a forehead flap proved advantageous, and the benefits of single-stage approaches were apparent. The patients recovered quickly after the surgery with complete resection of the osteoma and good aesthetic appearance. The flap adhered to the biopolymer implant, and the cosmetic appearance years after surgery remained decent. The gap between the bone and implant was less than 2 mm. The patients are highly satisfied with the symmetrical appearance of the reconstruction.

CONCLUSIONS

Advances in technology are allowing neurosurgeons unprecedented opportunities to design complex yet feasible single-stage craniofacial reconstructions that improve a patient's quality of life by enhancing facial contours, aesthetics, and symmetry.

Meningiomas of the pediatric skull base: a review

Pediatric skull base meningiomas are rare and complex clinical entities. Meningioma is a relatively uncommon brain tumor in children, and only ∼ 27% involve the skull base. Some evidence suggests that these tumors are more likely to be atypical or malignant in children than adults. The absence of female preponderance in pediatric meningiomas is reflected in the skull base subpopulation. Skull base meningiomas in children are most likely to be found in the anterior or middle fossa base, or involving the orbit and optic nerve sheath. Petroclival, suprasellar/parasellar, cerebellopontine angle, cavernous sinus, and foramen magnum tumors are very rare. Meningiomas constitute a small proportion of reported cases of pediatric skull base pathology, and they are entirely absent from many case series. Initial gross total resection is consistently associated with superior outcomes. Surgical approaches to the pediatric skull base must take additional factors into consideration including relatively smaller anatomy, immature dentition, incompletely aerated sinuses and air cells, and altered configurations of structures such as the pterional bony complex. Multidisciplinary expertise is essential to optimizing treatment outcomes.

The costs of skull base surgery in the pediatric population

Objectives To determine the costs of endoscopic endonasal surgery (EES) for pediatric skull base lesions. Methods Retrospective chart review of pediatric patients (ages 1 month to 19 years) treated for skull base lesions with EES from 1999 to 2013. Demographic and operative data were recorded. The cost of care for the surgical day, intensive care unit (ICU), floor, and total overall cost of inpatient stay were acquired from the finance department. Results A total of 160 pediatric patients undergoing EES for skull base lesions were identified. Of these, 55 patients had complete financial data available. The average total inpatient and surgical costs of care were $34, 056 per patient. Angiofibromas were the most costly: $59,051 per patient. Fibro-osseous lesions had the lowest costs: $10,931 per patient. The average ICU stay was 1.8 days at $4,577 per ICU day. The average acute care stay was 3.4 days at $1,961 per day. Overall length of stay was 4.5 days. Three cerebrospinal fluid leaks (4%) and two cases of meningitis (3%) occurred. One tracheostomy was required (1.5%). Conclusions EES is a cost-effective model for removal of skull base lesions in the pediatric population. Costs of care vary according to pathology, staged surgeries, length of ICU stay, and need for second operations.

Skull base surgery for tumors in children: long-term clinical and functional outcome

OBJECT

Skull base tumors in children are rare but require complex approaches with potential morbidity to the developing craniofacial skeleton, in addition to tumor-related morbidity. Reports of long-term clinical and functional outcome following skull base approaches in children are scarce. The authors report long-term outcome in children with tumors undergoing multidisciplinary skull base surgery.

METHODS

A retrospective analysis was undertaken of children undergoing surgery at a single institution between 1998 and 2008 for benign and malignant lesions of the anterior, middle, or posterior cranial base. Patients with craniopharyngioma, pituitary tumors, and optic glioma were excluded. Histology, surgical morbidity, length of hospital stay, progression-free survival, and adjuvant therapy were recorded. Functional and cognitive outcome was assessed prospectively using the Late Effects Severity Score (LESS).

RESULTS

Twenty-three children ranging in age from 13 months to 15 years underwent skull base approaches for resection of tumors during the study period. The median follow-up duration was 60 months. Tumor types included meningioma, schwannoma, rhabdomyosarcoma, neuroblastoma, angiofibroma, and chordoma. Complete resection was achieved in 12 patients (52%). Thirteen patients (57%) had benign histology. The median hospital stay was 7 days. There were 3 deaths, 1 perioperative and 2 from tumor progression. Two patients had CSF leakage (9%) and 2 developed meningitis. Two children (9%) had residual neurological deficit at last follow-up evaluation. Thirteen (59%) of 22 surviving patients received adjuvant therapy. The majority of the patients remain in mainstream education and 19 of the 20 surviving children have an LESS of 3 or lower.

CONCLUSIONS

Children tolerate complex skull base procedures well, with minimal surgical-related morbidity as well as good long-term tumor control rates and functional outcomes from maximal safe resection combined with adjuvant treatment when required.

Reconstruction of an extensive anterior skull base defect using a muscle-sparing rectus abdominis myocutaneous flap in a 1-year-old infant

Despite the recent advances in microsurgical techniques, reconstruction of extensive skull base defects using free flaps in pediatric patients presents a surgical challenge, and reports on skull base reconstruction in infants is quite limited. We present a case of reconstruction of an extensive anterior skull base defect using a rectus abdominis (RA) myocutaneous flap in a 1 year-old (14 months) infant. Sufficient coverage of the intracranial contents, good aesthetic results, and minimal growth disturbance at the donor site were achieved by the muscle-sparing RA flap transfer. To the best of our knowledge, this was among the youngest case of skull base reconstruction using a free flap. The feasibility of free flap transfer and flap selection in pediatric skull base reconstruction is discussed.

Review of skull base reconstruction using locoregional flaps and free flaps in children and adolescents

Tumors of the skull base are rare in children, and reconstruction in such patients has rarely been reported. We reviewed 16 cases of skull base reconstruction in patients under 18 years. The study group consisted of 10 boys and 6 girls, whose ages ranged from 2 to 17 years. Of the 16 cases, eight tumors were benign and eight were malignant. Defects were anterior in six cases, lateral in eight cases, and anterolateral in two cases. Reconstruction was performed with locoregional flaps in 11 cases and with free flaps in 5 cases. No significant difference was found between locoregional flaps and free flaps in total operative time, intraoperative blood loss, or postoperative hospital stay. However, in some cases, total operative time, reconstruction time, and blood loss increased to a degree unacceptable for pediatrics. Minor complications occurred in three patients and a major complication occurred in one case. Of four patients, three patients with postoperative complications had undergone chemoradiotherapy. Because of the physical weakness of pediatric patients, complicated reconstructive procedure should be avoided. We believe locoregional flaps will become the first choice for reconstruction. However, if patients have large, complex defects and have received radiotherapy, appropriate free flaps should be used to avoid postoperative complications.

Latissimus dorsi free flap reconstruction of anterior skull base defects

INTRODUCTION

Surgery of extensive skull base tumour results of a defect of soft and hard tissue and dura. Free flap reconstruction provides tissue to restore the defect and separate the intracranial content from the bacterial flora of the nasal fossae. Vertical and transverse rectus abdominis myocutaneous free flap are usually used. This study was designed to compare our experience of latissimus dorsi free flap reconstruction of extensive skull base defects after tumour resection with the literature concerning the use of other types of free flaps.

MATERIAL AND METHOD

All extensive skull base tumour resections with latissimus free flap reconstruction made in the head and neck oncology unit of the Institut Curie, Cancer Centre, between January 2004 and December 2009 were reviewed.

RESULTS

Two infectious complications were observed (11.7%), two cases of CSF leak (11.7%), one case of wound dehiscence following tumour resection comprising the nasal skin (5.9%) and one case of partial distal necrosis of the flap in a zone of skin resection (5.9%) were observed. No flaps were lost. Two latissimus dorsi donor site haematomas were observed (11.7%).

CONCLUSION

When reconstruction of extensive skull base defect need free flap, the latissimus dorsi free flap is a reliable solution.

Reconstruction of pediatric cranial base defects: a review of a single microsurgeon's 30-year experience

BACKGROUND

For the past 30 years, microsurgical free tissue transfer has enabled the reconstruction of pediatric cranial base lesions formerly believed to be refractory to surgical therapy. Due to the relative rarity of these oncologic processes and the highly specialized requirements for their treatment, few large-scale reviews of microsurgical reconstruction of pediatric cranial base lesions have been published to date.

METHODS

A review of all free tissue transfer reconstructive procedures undertaken by a single microsurgeon for pediatric cranial base defects was performed for operations occurring between 1977 and 2007. All procedures were performed at a single institution on patients ranging from infancy to 16 years of age. Data were culled from a combination of patient charts, hospital records, radiographic studies, and clinical photographs.

RESULTS

Thirty patient charts were analyzed from the defined 30-year period. The average patient age at the time of diagnosis was 5.3 years (SD = 4.9 years). The most common primary diagnosis was rhabdomyosarcoma (n = 10; 33%). Most patients received chemotherapy (n = 26; 87%) or radiotherapy (n = 16; 53%). Most patients required extirpative hemimaxillectomy or hemimandiblectomy, necessitating reconstruction of intraoral structures in 16 children (53%). Forty free tissue transfers were performed; the most commonly used donor site was the rectus abdominis muscle (n = 19; 48%), followed by the fibula (n = 13; 30%), scapula (n = 5; 13%), latissimus dorsi muscle (n = 2; 5%), and radial forearm (n = 1; 3%). Reconstructive adjuncts included nonvascularized bone grafts (n = 13; 43%) and sural nerve grafts (n = 6; 20%). Short-term perioperative complications were relatively minor; no flap losses were recorded. The most common anticipated long-term complications included growth disturbances (n = 10; 33%), resorption of nonvascularized bone grafts (n = 8; 27%), and soft tissue atrophy/contracture (n = 8; 27%). Most patients studied were noted to be surviving (n = 22; 73%), with an average age of 19.2 years (SD, 10.1 years); among those patients who had died (n = 8; 27%), the average age at death was 14.6 years (SD, 6.2 years). The preponderance of patients who had died received their initial surgery and reconstruction during the first 15 years of this study period (n = 7; 88% of subgroup), with death most often due to complications related to extension of the original malignancy through the cranial base.

CONCLUSIONS

As advances in oncologic therapy continue to improve survival among pediatric patients experiencing malignancies involving the cranial base, microsurgery simultaneously continues to enable robust options for postextirpative reconstruction and therefore provides a major benefit to the ongoing care of these individuals.

Outcome of craniofacial surgery in children and adolescents with malignant tumors involving the skull base: an international collaborative study

BACKGROUND

The aim of the study was to characterize the distribution of anterior skull base (ASB) cancers in the pediatric population and to identify predictors of outcome.

METHODS

This was an international study of 1307 patients undergoing craniofacial surgery for malignant tumors; 6.4% (n = 84) among these were <or=21 years old.

RESULTS

The most common histologic type was sarcoma (40%), followed by squamous cell carcinoma (14%). Higher incidence of tumors was found in older children (7.5-21 years) compared to younger children. The 5-year disease-specific and overall survival rates were 61% and 55%, respectively (median follow-up of 30 months). The best prognosis was associated with low-grade sarcomas and the worst with salivary and squamous cell carcinomas. High-grade sarcoma represented an intermediate risk group. On multivariate analysis, prior radiotherapy and histology were independent predictors of survival.

CONCLUSION

Surgery for malignant tumors involving the ASB is feasible and safe in children. Histology is significant determinant of poor outcome in this population.

Spectrum of skull base tumors in children and adolescents: a series of 42 patients and review of the literature

OBJECTIVE

This study aims to contribute to the collective experience with the treatment of those skull base tumors exceptionally arising in children and adolescents.

MATERIALS AND METHODS

We retrospectively reviewed 42 patients younger than 19 years and operated on for a skull base tumor between 1992 and 2002. We analyzed data regarding patient age, histology, tumor location, extent of resection, postoperative complications, and adjuvant therapies. Long-term outcomes were also tracked (functional sequelae, recurrence, mortality).

CONCLUSION

The median age was 13.75 years. Twenty-two patients harbored a malignant tumor. Gross total resection was achieved for 78% of cases. Transient postoperative cerebrospinal fluid leak or infection affected ten patients, suggesting the need for reconstructive techniques. Nineteen patients received adjuvant therapy. Recurrence rate was 47%. At the end of the follow-up (median = 63 months), 14% of patients had a neurological deficit and 30% were dead. Middle cranial base tumors were associated with a poor prognosis.