Surgical treatment of transsphenoidal encephaloceles: transpalatal versus combined transpalatal and transcranial approach

Trans-sellar-trans-sphenoidal encephalocele presenting as nasal obstruction in an infant: a case report and systematic review of existing reports

Trans-sellar trans-sphenoidal encephalocele is a rare congenital anomaly, with only around 20 cases having been documented in literature around the world. Surgical repair of these defects in the pediatric population commonly uses either the transcranial or the transpalatal approach, with the choice of approach being individualized based on the clinical features, age, and associated defects present in the patient. Here, we document a case of a 4-month-old child who presented to us with nasal obstruction, who was diagnosed with this rare entity and successfully underwent a transcranial repair for the same. We also provide a systematic review of all existing case reports that have described this rare condition in the pediatric population, as weel as the different surgical approaches used in each case.

Repair of Giant Anterior Skull Base Encephalocele Containing Intralesional Eloquent Brain: Technical Note

BACKGROUND

Encephaloceles are herniations of intracranial neural tissue and meninges through defects in the skull. Basal encephaloceles are rare anterior skull base defects incident in 1 in 35,000 live births. Sphenoethmoidal encephaloceles are even more uncommon, with an incidence of 1 in 700,000 live births. Anterior skull base encephaloceles may be life-threatening in infants, presenting as airway obstruction and respiratory compromise. They can also present with cerebrospinal fluid (CSF) rhinorrhea, purulent nasal drainage, or meningitis.

OBJECTIVE

To report a novel technique for repairing a giant sphenoethmoidal encephalocele containing eloquent neural tissue.

METHODS

A 16-mo-old girl presented with progressive airway obstruction from a giant sphenoethmoidal encephalocele that filled her oral cavity. She had multiple congenital anomalies including agenesis of the corpus callosum and cleft lip and palate. Computed tomography showed complete absence of the bony anterior cranial base, and magnetic resonance imaging demonstrated the presence of the pituitary gland and hypothalamus in the hernia sac.

RESULTS

We repaired the encephalocele using a combined microsurgical and endoscopic multidisciplinary approach working through transcranial, transnasal, and transpalatal corridors. The procedure was completed in a single stage, during which the midline cleft lip was also repaired. The child made an excellent neurological and aesthetic recovery with preservation of pituitary and hypothalamic function, without evidence of CSF fistula.

CONCLUSION

The authors describe a novel multidisciplinary technique for treating a giant sphenoethmoidal encephalocele containing eloquent brain. The cleft lip was also repaired at the same time. The ability to work through multiple corridors can enhance the safety and efficacy of an often-treacherous operative endeavor.

A hybrid simulation model for pre-operative planning of transsphenoidal encephalocele

Congenital transsphenoidal encephalocele (CTE) surgical correction is a challenging procedure. Although rare, this anomaly, characterized with neural herniation elements, including the pituitary gland or optic pathway through the sphenoid bone with anatomical alteration, can be presented in many different ways and should be individually analyzed. Significant advances in medical technology and the 3D models may simulate the complex anatomical relations of the human body. Nowadays, medical education relies on the availability of standardized materials that can reliably emulate human anatomy. Therefore, realistic anatomical models have become an alternative for cadavers or animal specimens. In this technical note, the authors present a new technique to create personalized models that combine 3D printing, molding, and casting to create an anatomically and tactilely realistic model based on magnetic resonance and computerized tomography images. Produced from different silicon types, the model recreated the anatomic alterations precisely, allowing a multidisciplinary team to determine the adequate surgical approach for this patient. We describe a case of congenital transsphenoidal encephalocele of a 3-year-old boy, whose surgical correction was planned using a hybrid model. The technical description of the model is given in detail. This new hybrid model allowed a detailed discussion of the surgical approach aspects by having tissues of different consistencies and resistances and a very high prediction rate. This approach may allow a reduction in surgery time and possible complications after operative procedures.

Basal encephalocele: surgical strategy and functional outcomes in the Tokyo experience

OBJECTIVE

The basal encephalocele (BEC) is the rarest form of encephalocele, with an incidence of about 1/35,000 live births. The incidence of its subtype, sphenoidal BEC, is even lower at about 1/700,000 live births. The aim of this study was to propose the optimal surgical approach to repairing BEC, with special attention to the reconstruction of the skull base bone defect.

METHODS

Fourteen consecutive pediatric patients with BEC who underwent surgical repair between March 2004 and March 2020 (10 boys and 4 girls, age 25 days to 7 years, median age 4 months) were enrolled. The follow-up period of the surviving patients ranged from 53 to192 months (mean 119.8 months). The patient demographics, BEC subtypes, preoperative clinical condition, radiographic findings, surgical procedures, and postoperative course were retrospectively analyzed.

RESULTS

There were 4, 8, and 2 cases of sphenoidal BEC, sphenoethmoidal BEC, and ethmoidal BEC, respectively. The size of the bone defect was small in 3 patients, medium in 7, and large in 4 patients. All the patients with sphenoethmoidal and ethmoidal BEC showed associated congenital anomalies other than cleft palate. In total, 25 operations were performed. Two patients underwent multiple operations, whereas the remaining 9 patients received only 1 operation. The transoral transpalatal approach was the initial procedure used in all 14 patients. The transfrontobasal approach was applied as an additional procedure in 2 patients and as part of a 1-stage combined operation in 2 patients. Autograft bone alone was used for skull base reconstruction in 17 early operations. A titanium mesh/plate was used in the remaining 8 operations without any perioperative complications. All BECs were successfully repaired. Three patients died during the clinical course due to causes unrelated to their surgery. All but one of the surviving patients started growth hormone replacement therapy before school age.

CONCLUSIONS

Based on the authors' limited experience, the key to successful BEC repair involves circumferential dissection of the BEC and a firm reconstruction of the skull base bone defect with a titanium plate/mesh. The transoral transpalatal approach is a promising, reliable procedure that may be used in the initial operation. When a cleft palate is absent, transnasal endoscopic repair is recommended. The transfrontobasal approach should be reserved for cases with a huge BEC and other anomalies. Long-term prognosis is apparently favorable in survivors.

Sphenoethmoidal meningoencephalocele with variable hypopituitarism: A case report and review of literature

Sphenoethmoidal meningoencephalocele is a rare congenital meningocele with unclear clinical course. Its clinical symptoms are diverse, and this disease is widely observed across all ages. The prognosis of this disease depends on the severity of the central nervous system complications. We reported a case of sphenoethmoidal meningoencephalocele incidentally discovered in a 2-yr-old patient, with the subsequent appearance of diabetes insipidus at school age. An endocrinological evaluation performed when the patient was nine years old using the TRH/CRH/LH-RH load test showed a low response of gonadotropins and slightly hyper-response and normal response of ACTH and TSH, respectively. GH provocative tests indicated severe GH deficiency. Desmopressin and GH treatment efficiently improved his growth rate and quality of life. His pituitary function had presumably been normal from the neonatal period to infancy, but the dysfunction gradually progressed over the next few years along with his physical growth. The symptoms were suspected to be the product of the natural course of his hypothalamus or pituitary gland degeneration, or were otherwise due to gradual damage by chronic mechanical compression or extension. These findings underscore the importance of conducting careful systemic management in the long term, specifically with respect to the endocrinological evaluation of sphenoethmoidal meningoencephalocele.

Iatrogenic meningoencephalocele after traumatic perforation of the cribriform plate during nasal intubation of a preterm infant

Traumatic iatrogenic meningoencephaloceles infants are rare and there is no consensus on management in the literature. This article presents a case of a meningoencephalocele diagnosed 15 months after a traumatic perforation of the cribriform plate due to a difficult intubation of a preterm infant that was treated by an endoscopic endonasal surgery. A close collaboration between pediatricians and ENT surgeons appears essential for early diagnosis and management. Endoscopic endonasal approach for meningoencephalocele management has several advantages and is a safe procedure when performed by an experienced surgeon.

Modified endoscopic endonasal approach with a minimally invasive transoral approach-an adjunct to infrapetrous approaches

OBJECTIVES/HYPOTHESIS

To evaluate the potential of a minimally invasive transoral-transpalatal approach (MITA) to the retrocarotid petrous apex, as an adjunct to endoscopic endonasal approaches (EEAs).

STUDY DESIGN

Cadaver study.

METHODS

Five cadaveric specimens were dissected raising an inverted U-shaped palatal mucoperiosteal flap, and drilling a rectangular palatotomy (between the greater palatine foramens, and just anterior to the palatine aponeurosis). This allowed a transpterygoid EEA with cross-court access (contralateral line of sight), followed by an extradural clivectomy that exposed the petroclival junction bilaterally. Surgical targets were marked on the posterior and medial surface of the petrous internal carotid artery (ICA), at its anterior genu, midhorizontal portion, and posterior genu. For each target and approach, the surgical freedom and angles of approach (in the horizontal and vertical planes) were calculated and statistically compared.

RESULTS

Compared to EEA, the MITA resulted in greater surgical freedom for all targets, with the highest values at the anterior genu (1,661.37 mm² vs. 312.76 mm² , P <.001), and maintaining superiority in this regard all the way to the posterior genu (847.84 mm³ vs. 138.91 mm³ , P < .005). MITA also offered greater angles of approach for all targets.

CONCLUSIONS

This study suggests that the MITA may be indicated to supplement the exposure provided by a transpterygoid EEA. This technique, associated with low potential morbidity, offers an alternative to internal carotid lateralization while managing extradural lesions that are adjacent to the petrous ICA.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:339-343, 2019.