Satoshi Shirakura

Anatomical feature of the middle cranial fossa in fetal periods: Possible etiology of superior canal dehiscence syndrome

Abstract Conclusion: Different from adults, the superior semicircular canal (SSC) protrudes into the cranium during the fetal period. This might cause adhesion of the membranous labyrinth to dura as the bony labyrinth develops much later than the membranous labyrinth. This adhesion interferes with ossification and leads to a bony defect in the SSC. Objectives: The purpose of this study was to investigate a possible etiology of superior canal dehiscence syndrome (SCDS) from a view point of ontogeny. Methods: Forty-two adult cadavers and 4 fetal cadavers were used for macroscopic observation of the middle cranial fossa (MCF). In addition, six fetuses underwent computed tomography (CT) examinations. The volume data of the CT obtained from four adults were also used for comparison. Using these CT data, we investigated the anatomic relationship between the MCF and SSC. Results: The SSC and the cochlea in fetuses protruded into the cranium in macroscopic anatomy and CT examination. On the other hand, the SSC of all adults was completely or mostly buried in the temporal bone.

Parapharyngeal space tumors: Anatomical and image analysis findings

OBJECTIVE The parapharyngeal space (PS) is defined as the deepest space in the neck and it consists of the pre- and post-styloid regions. PS tumors originating in these regions are thought to dislocate the carotid artery (CA) in either the posterior or anterior direction. To determine the precise anatomy of the PS and its relationship with the CA in diagnostic images, we conducted cadaveric and imagining analysis. MATERIALS AND METHODS We examined the posterior and lateral aspects of the PS in three cadavers. We also examined 17 patients who suffered from PS tumors, in which the carotid artery was dislocated (CA), then compared the results with surgical and pathological findings. RESULTS The anterior part of the PS was mainly composed of fatty tissue and is generally referred to as the pre-styloid region of the PS. In the posterior of this fatty region, blood vessels and nerves were tightly covered with muscles and adjacent fascias to form a compact musculo-fascial structure containing the CA, jugular vein, vagal, glossopharyngeal, accessory and sympathetic nerves, and a portion of the hypoglossal nerves. The hypoglossal nerves emerged from the hypoglossal canal posterior to this structure and coursed behind it, entering it at the upper third of the PS. These anatomical findings indicated that the PS was actually comprises of three regions. Image analysis showed that the CA was dislocated in the postero-lateral direction by a pleomorphic adenoma originating from the parotid gland and by a trigeminal schwannoma, both of which were pre-styloid tumors. On the other hand, the post-styloid tumors did not always dislocate the CA in the anterior direction. Tumors that developed within the musculo-fascial structure such as those of the carotid body tumor or sympathetic nerve schwannoma dislocated the CA from both the antero- to the postero-lateral directions. A hypoglossal nerve schwannoma originating from the most posterior part of the PS, which was behind the musculo-fascial structure dislocated the CA in the anterior direction. CONCLUSION The present findings indicated that the post-styloid region of the PS is considered to consist of two regions. As the CA is a component of this musculo-fascial structure, tumors originating from it that are defined as post-styloid did not always displace the CA in the anterior direction. Such anatomical recognition is helpful for diagnostic imaging of PS tumors.

The approaches and outcomes of skull base surgery for pediatric sarcoma after initial therapy

OBJECTIVE Surgical removal of the residual pediatric sarcoma after initial therapy is common; however, that in the skull base area still presents a formidable challenge. We reviewed the approaches and outcomes of skull base surgery for pediatric sarcoma. METHODS Thirteen patients with pediatric sarcoma who received skull base surgery were reviewed retrospectively. Tumor sites, surgical approach, complications, regional recurrence after surgery, and survival rate were analyzed. RESULTS The residual tumor sites were the infratemporal fossa (8), nasal cavity and paranasal sinus (4) and orbit with anterior skull base invasion (1). Coronal skin incision (1), that with preauricular skin incision (7) and facial dismasking flap (5) were applied to patients as the skin preparation. Following skin preparations, anterior skull base surgery with frontal craniotomy (3), infratemporal fossa approach with temporal craniotomy (5), and anterior-lateral skull base with front-temporal craniotomy (1) were performed. Tumors were removed with a sufficient surgical field in all patients. Facial nerve palsy (9), facial deformity (4), orbital complications (diplopia, decreased visual acuity, narrowing of visual field) (2) and occlusal imbalance (1) occurred. However, facial palsy, diplopia and occlusal imbalance subsided gradually. Local recurrence occurred in 6 cases and distant metastasis was observed in 4 cases. The overall 5-years survival rate was 51.9% (Kaplan-Meier method). CONCLUSION These tumors were safely removed with minimum morbidity. Skull base surgery is recommended to remove residual pediatric sarcoma after the initial treatment.

Complex lower face reconstruction using a combined technique of Estlander flap and subscapular artery system free flaps.

When advanced mandibular carcinoma is resected, the defect may include lip and oral commissure. Free flap insertion is commonly used to reconstruct the lip defect. Although improvements in the oral reconstructive method via free flap use have been reported, functional and aesthetic results of the oral sphincter remain limited. This case report describes two individuals presenting with massive lower face defects, including a lower lip defect and a mandibular bone defect. Reconstruction was accomplished using the Estlander flap and free subscapular system of flaps. In both cases, the free subscapular artery system flap was elevated from the mandibular bone defect and other mucosal defect. The lower lip and oral commissure defect was reconstructed via Estlander flap. Free flaps survived 100% and both cases healed without complication. Patients regained good oral sphincter function with no reports of drooling. Thus, in cases involving massive lower face resection, including that of the lower lip and mandibular bone, this method of reconstruction when combined with lip-switch flap and subscapular artery system flap can prove to be useful.

Clinical features of IgG4-related rhinosinusitis

PURPOSE IgG4-related disease is a systemic disease that affects various organs of the body. Aim of this study is to elucidate the clinical characteristics of IgG4-related rhinosinusitis. MATERIAL AND METHODS Clinical features, laboratory findings, radiological and endoscopic findings, associated disease, treatment and prognosis were retrospectively examined in 10 patients with IgG4-related rhinosinusitis. RESULTS The age was 59.1±11.3 years old and male-to-female ratio was 1:1. The chief nasal complaints were hyposmia (n=4), nasal obstruction (n=3), and nothing (n=3). Serum IgG4 levels were elevated in all patients and the value was 740.4±472.4mg/dl. Other IgG4-related diseases were associated in all 10 patients, including IgG4-related sialadenitis (n=6), IgG4-related dacryoadenitis (n=5), and autoimmune pancreatitis (n=5). Imaging findings on CT/MRI were obstruction of the way of elimination (n=10), thickening of the sinus mucous membrane (n=10), and fluid in the sinus (n=6). All of the cases had bilateral findings. Nasal endoscopic findings were chiefly deviated nasal septum (n=5), polyps (n=4), edema of the mucous membrane (n=3). Histologically, abundant infiltration of IgG4 positive plasma cell and lymphocyte and an elevated IgG4+/IgG+ cell ration was detected in all 8 patients and 5 patients, respectively. Endoscopic sinus surgery was performed in 8 patients. Eight patients were treated with steroid therapy for other associated IgG4-related diseases. Symptoms improved in all 6 patients after an initial treatment (endoscopic surgery (n=5) and steroids (n=1)), but one patient suffered relapse. CONCLUSIONS IgG4-related rhinosinusitis is a distinct entity of IgG4-related disease, and is associated in patients with multiple IgG4-related diseases.

The selection of treatment strategy for stage III, IV laryngeal and hypopharyngeal squamous cell carcinoma: —an evaluation of predictable parameters for concurrent chemoradiotherapy—@@@―化学放射線同時併用療法の選択基準についての考察―

In the treatment strategy for advanced laryngeal or hypopharyngeal cancer, it is not so easy to decide whether patient should be performed concurrent chemoradiotherapy (CCRT) or wide resection with total laryngectomy. One hundred-fifty three patients were divided into two groups according to the modality for primary site ; CCRT group and the other wide resection group, and we retrospectively examined whether we could predict the case of having high sensitivity and curative possibility to CCRT. Clinical parameters ; T stage, subsite of tumor, tumor volume, existence of laryngeal paresis and tumor growth pattern, all of them were not predictable. The response to induction chemotherapy was not also predictable. Relapse free survival rate, regional free survival rate and disease specific survival rate were 58.2%, 55.2% and 30.1% in CCRT group and 91.6%, 76.4% and 61.1% in wide resection group and there were significant differences between them.

A novel permanent tracheostomy technique for prevention of stomal stenosis (triangular tracheostomy).

OBJECTIVE Stenosis of a permanent tracheostoma after total laryngectomy lowers postoperative quality of life (QOL), and its prevention is clinically important. METHODS From April 2003 to March 2009, the authors performed 87 permanent tracheostomies. For the purpose of prevention of tracheostomal stenosis, we had applied new technique from October 2005. RESULTS The incidence of the tracheostomal stenosis was retrospectively reviewed. Until September 2005, conventional permanent tracheostomy was applied for 33 cases and tracheostomal stenosis developed in 6 cases (18.2%). On the other hand, stenosis did not develop in any of the 54 cases in which the new technique was used. The triangular method was significantly superior to the conventional method in preventing stenosis. Stomal recurrence did not develop in either technique. CONCLUSION The key point of the new technique is as follows: at the upper end of trachea, the posterior part of tracheal cartilage is preserved and the anterior edge of the tracheostoma is made much lower. The shape of the tracheostoma approximates a triangle, and the area is greater than with other methods. From our experience, this technique is safe and effective for the prevention of tracheostomal stenosis.