The Flap Sandwich Technique for a Safe and Aesthetic Skull Base Reconstruction.

For safe and reliable skull base reconstruction combined with repair of cranial bone defects, we introduce the flap sandwich technique in this study. A titanium mesh is often used to repair structural cranial bone defects because it has less donor site morbidity and is easy to handle. However, titanium mesh has disadvantages of exposure and infection postoperatively. To improve surgical outcomes, we applied the flap sandwich technique to 3 cases of skull base reconstruction combined with cranial bone defect repair. Two anterior skull base defects and 1 middle skull base defect were included in this study. The subjects were all women, aged 30, 58, and 62 years. One patient had former multiple craniotomies and another patient had preoperative radiotherapy. The flap sandwich technique involves structural cranial bone reconstruction with a titanium mesh and soft tissue reconstruction with a chimeric anterolateral thigh free flap. First, the dead space between the repaired dura and the titanium mesh is filled with vastus lateralis muscle, and then structural reconstruction is performed with a titanium mesh. Finally, the titanium mesh is totally covered with the adiposal flap of the anterolateral thigh free flap. The muscle flap protects the dead space from infection, and the adiposal flap covers the titanium mesh to reduce mechanical stress on the covered skin and thus prevent the exposure of the titanium mesh through the scalp. By applying this technique, there was no intracranial infection or titanium mesh exposure in these 3 cases postoperatively, even though 2 patients had postoperative radiotherapy. Additionally, the adiposal flap could provide a soft and natural contour to the scalp and forehead region, and this gives patients a better facial appearance even though they have had skull base surgery.

Epicutaneous administration of papain induces IgE and IgG responses in a cysteine protease activity-dependent manner.

BACKGROUND: Epicutaneous sensitization to allergens is important in the pathogenesis of not only skin inflammation such as atopic dermatitis but also "atopic march" in allergic diseases such as asthma and food allergies. We here examined antibody production and skin barrier dysfunction in mice epicutaneously administered papain, a plant-derived occupational allergen belonging to the same family of cysteine proteases as mite major group 1 allergens. METHODS: Papain and Staphylococcus aureus V8 protease were patched on the backs of hairless mice. Transepidermal water loss was measured to evaluate the skin barrier dysfunction caused by the proteases. Papain or that treated with an irreversible inhibitor specific to cysteine proteases, E64, was painted onto the ear lobes of mice of an inbred strain C57BL/6. Serum total IgE levels and papain-specific IgE and IgG antibodies were measured by ELISA. RESULTS: Papain and V8 protease patched on the backs of hairless mice caused skin barrier dysfunction and increased serum total IgE levels, and papain induced the production of papain-specific IgG1, IgG2a, and IgG2b. Papain painted onto the ear lobes of C57BL/6 mice induced papain-specific IgE, IgG1, IgG2c, and IgG2b, whereas papain treated with E64 did not. IgG1 was the most significantly induced papain-specific IgG subclass among those measured. CONCLUSIONS: We demonstrated that the epicutaneous administration of protease not only disrupted skin barrier function, but also induced IgE and IgG responses in a manner dependent on its protease activity. These results suggest that protease activity contained in environmental sources contributes to sensitization through an epicutaneous route.

Usability of the middle temporal vein as a recipient vessel for free tissue transfer in skull-base reconstruction.

In skull-base reconstruction, finding appropriate recipient veins is difficult if the patient has undergone previous craniotomy or requires multiple drainage vessels, because of postoperative scarring and the limited number of veins in the temporal region. Therefore, we have used the middle temporal vein (MTV) to overcome these problems. We examined the presence and caliber of the MTV in 12 patients undergoing skull-base reconstruction. The MTV was identified in all cases and used for reconstruction, alone or with the superficial temporal vein (STV), in 8 patients without postoperative flap loss and was only measured in 4 patients. The caliber of the MTV was significantly greater than that of the STV, and there was no significant difference between the usage of the MTV and STV in the length of reconstruction time. Therefore, the MTV is of an appropriate caliber, and its use does not require complicated procedures as alternative recipient vessels.

Reliability of and indications for pericranial flaps in anterior skull base reconstruction.

Owing to changes in the treatment of skull-base tumors, such as perioperative radiotherapy and advances in approaching the skull base, the use of pericranial flaps should be reconsidered. Therefore, we reviewed the reliability of and indications for pericranial flaps in 26 cases in terms of patient background, the effects of preoperative and postoperative treatment, and the pattern of blood circulation. Flaps were harvested as 25 anteriorly based and 4 laterally based. As a result, postoperative complications were observed in 4 patients. No other risk factors, except for heavy smoking, were observed relative to patient background. Sixteen patients had perioperative radiotherapy, and complication rate was significantly higher in patients with preoperative radiotherapy than patients without preoperative radiotherapy (P=0.014). However, no complications, such as cerebral spinal fluid leakage and intracranial infection, were observed in patients receiving postoperative radiotherapy. Laterally based pericranial flaps had a high complication rate (25%), but it was not significantly higher than anteriorly based flaps (P=0.467). Five anteriorly based flaps were harvested with less feeding vessels as usual because of applying dismasking flap approach, but it did not lead to increasing in complication rate. We conclude that a pericranial flap can be used for skull base reconstruction even if postoperative radiotherapy is planned but might be avoided for patients who have received preoperative radiotherapy. In addition, particular care and flap design should be taken to preserve sufficient vascularity when pericranial flaps are raised as laterally based and less feeding vessels as usual.

Facial dismasking flap for removal of tumors in the craniofacial region.

OBJECTIVE: This study was aimed at estimating the usefulness of the facial dismasking flap for craniofacial surgery. STUDY DESIGN: Anatomical study and retrospective case study. MATERIALS AND METHODS: The facial dismasking flap is a combination of a coronal skin incision and a circumpalpebral incision. By adding a circumpalpebral incision, the skin can be detached from the orbital structures and the coronal skin flap can be elevated more inferiorly together with the facial nerves and muscles. We retrospectively reviewed patients who underwent the facial dismasking flap with regard to the extent of the surgical field and resectability under this flap. Postoperative facial scarring and movements were also evaluated. Facial palsy was estimated according to the House-Brackmann grading system. RESULT: Twenty-three patients with tumors in various locations, such as, the nasal cavity, paranasal sinus, zygoma, and infratemporal fossa, who had undergone a facial dismasking flap, were studied. Sufficient surgical fields were obtained for removal of the tumor in all patients. Tumors were totally resected in 21 patients and were subtotally resected in two patients to avoid optic nerve damage. Facial nerves were anatomically preserved and facial scarring was minimal in all patients. No facial palsy remained in any patients except one who showed a deterioration of the facial palsy (House-Brackmann grade V-VI). CONCLUSION: This flap allows the surgeon to obtain wide exposure of the upper two-thirds of the facial skull. Moreover, damage to the facial skin is minimal and facial movements are well preserved. This technique is not well known to head and neck surgeons, and this is the first comprehensive report of this technique applied to removal of craniofacial lesions.

Adipose-derived stem cells express higher levels of type VII collagen under specific culture conditions.

Type VII collagen (Col7) is a major component of the anchoring fibrils at the dermoepidermal junction. Adipose-derived stem cells (ADSCs) are a cell population highly useful in regenerative medicine because of their ease of isolation and their potential for multilineage differentiation. Based on the observations that K14 was expressed in undifferentiated ADSCs and the expression was downregulated after differentiation into adipocytes, we speculated that ADSCs are keratinocyte stem/progenitor cells. ADSCs were co-cultured with fibroblasts on type IV collagen in a medium containing all-trans retinoic acid and bone morphogenetic protein 4. At day 14 of culture in keratinocyte serum-free medium, the cells were harvested and subjected to immunofluorescence, flow cytometry, real-time PCR, and western blotting. Approximately, 45% of ADSCs were immunostained positively for anti-human cytokeratin 10, and approximately 80% were stained positively for Col7. Flow cytometry, real-time PCR, and western blotting also confirmed that differentiated ADSCs expressed higher levels of Col7. These findings support the therapeutic potential of ADSCs, not only for wound healing, but also for the correction of Col7 deficiencies.

Pituitary apoplexy manifesting as diffuse subarachnoid hemorrhage.

A 46-year-old woman presented with hemorrhage from a non-functioning pituitary adenoma manifesting as sudden onset of severe headache. Computed tomography demonstrated diffuse subarachnoid hemorrhage (SAH) and a suprasellar mass with intratumoral hematoma. The patient underwent transnasal transsphenoidal removal of the pituitary adenoma. This type of SAH with intratumoral hematoma simulates rupture of an anterior cerebral artery aneurysm.

Epicutaneous Allergic Sensitization by Cooperation between Allergen Protease Activity and Mechanical Skin Barrier Damage in Mice.

Allergen sources such as mites, insects, fungi, and pollen contain proteases. Airway exposure to proteases induces allergic airway inflammation and IgE/IgG1 responses via IL-33-dependent mechanisms in mice. We examined the epicutaneous sensitization of mice to a model protease allergen, papain; the effects of tape stripping, which induces epidermal barrier dysfunction; and the atopic march upon a subsequent airway challenge. Papain painting on ear skin and tape stripping cooperatively promoted dermatitis, the skin gene expression of proinflammatory cytokines and growth factors, up-regulation of serum total IgE, and papain-specific IgE/IgG1 induction. Epicutaneous sensitization induced T helper (Th) 2 cells and Th17 differentiation in draining lymph nodes. Ovalbumin and protease inhibitor-treated papain induced no or weak responses, whereas the co-administration of ovalbumin and papain promoted ovalbumin-specific IgE/IgG1 induction. Wild-type and IL-33-deficient mice showed similar responses in the epicutaneous sensitization phase. The subsequent airway papain challenge induced airway eosinophilia and maintained high papain-specific IgE levels in an IL-33-dependent manner. These results suggest that allergen source-derived protease activity and mechanical barrier damage such as that caused by scratching cooperatively promote epicutaneous sensitization and skin inflammation and that IL-33 is dispensable for epicutaneous sensitization but is crucial in the atopic march upon a subsequent airway low-dose encounter with protease allergens.

Dilation of spinal epidural veins caused by spontaneous intracranial hypotension: case report.

A 30-year-old woman presented with headache which occurred when standing up from a recumbent position. Magnetic resonance (MR) imaging of the brain revealed slightly diffuse enhancement of the dura mater and two ventral extradural spinal flow voids in the supine position. Radionuclide cisternography identified cerebrospinal fluid leakage localized below the cervical level. Vertebral angiography demonstrated two dilated ventral extradural veins. The patient was treated by conservative therapy and improved with rest. The unusual clinical presentation with dilation of two epidural veins indicates the diagnostic value of MR imaging in cases of spontaneous intracranial hypotension.

Keratinocyte progenitor cells reside in human subcutaneous adipose tissue.

The differentiation of adipose-derived stem cells (ASCs) towards epithelial lineages has yet to be demonstrated using a standardized method. This study investigated whether keratinocyte progenitor cells are present in the ASC population. ASCs isolated from subcutaneous adipose tissue were cultured and examined for the expression of the keratinocyte progenitor markers p63 and desmoglein 3 (DSG3) by immunofluorescence microscopy and flow cytometry. In addition, p63 and DSG3 expression levels were assessed before and after differentiation of ASCs into adipocytes by real-time PCR and western blot analysis, as well as in subcutaneous adipose tissue by real-time reverse transcriptase polymerase chain reaction. Both markers were expressed in ASCs, but were downregulated after the differentiation of ASCs into adipocytes; p63-positive cells were also detected in subcutaneous adipose tissue. ASCs co-cultured with human fibroblasts and incubated with all-trans retinoic acid and bone morphologic protein 4 showed an upregulation in DSG3 level, which was also increased in the presence of type IV collagen. They also showed an upregulation in cytokeratin-5 level only in the presence of type IV collagen. These results provide the demonstration that keratinocyte progenitor cells reside in subcutaneous adipose tissue.

Manual occipital ventricular puncture for cerebrospinal fluid shunt surgery: can aiming be standardized?

The manual occipital ventricular puncture is a standard surgical procedure, but specific targeting has not received sufficient attention despite the experience of anatomical disorientation. This study tried to identify an exact site for the ideal trajectory with this method, especially in the sagittal plane, which avoids contact with the choroid plexus that may be the major source of complications. A total of 44 consecutive adult cases undergoing cerebrospinal fluid shunting through the occipital route for hydrocephalus were retrospectively reviewed for the following: correlations between burr hole site, direction of puncture, and location of the ventricular catheter based on postsurgical radiological studies; calculation of the ideal trajectory to place the catheter tip in the anterior horn of the lateral ventricle without contact with the choroid plexus through the standard occipital burr hole. In addition, the relationships between the location of the ventricular structure, the cranial base line connecting the nasion and inion, and the size of the ventricle were evaluated. Incorrect catheter emplacement was found in five cases, which suggested that this procedure using the standard burr hole site and aim point might result in incorrect catheter placement. The ideal external aim points were widely distributed because of the variable heights of ventricular structures from the cranial baseline. No correlation between the locations of the anatomical points and ventricular size was found. The present study could not define a standard external aim point. Tailored preoperative planning of the trajectory is recommended.

Cerebral infarction and fluid collection due to an enlarged dissecting aneurysm of the middle cerebral artery--case report.

A 53-year-old man presented with cerebral infarction associated with a dissecting aneurysm of the left middle cerebral artery (MCA), with enlargement and fluid collection. Anticoagulant therapy was performed as the first stage treatment for cerebral infarction. Serial magnetic resonance imaging showed that the dissecting aneurysm had enlarged and fluid collection adjacent to the aneurysm had developed since the first admission. Surgery was performed to ligate the MCA proximal to the aneurysm. Intraoperative findings showed the branch of the MCA was obstructed by intramural hemorrhage of the aneurysm dome. Histological examination showed direct obstruction of the MCA branch artery by intramural hemorrhage of aneurysm dome had caused the cerebral infarction and the fluid collection surrounding the aneurysm resulted from minor leakage or exudation of intramural hemorrhage to the outer surface of the dissecting aneurysm.

Idiopathic spinal cord herniation associated with calcified thoracic disc extrusion--case report.

A 48-year-old man presented with idiopathic spinal cord herniation associated with calcified thoracic disc extrusion at the T7-8 intervertebral level, manifesting as Brown-Sequard syndrome at the thoracic level persisting for 20 years. Preoperative magnetic resonance imaging and computed tomography myelography revealed ventral displacement of the spinal cord and extrusion of a calcified disc at the T7-8 intervertebral level. At surgery, the spinal cord herniation at this level was released from the dura mater and carefully returned to the dural sac. An extruded calcified thoracic disc was found just below the dural defect at the same level. The development of idiopathic spinal cord herniation is associated closely with a defect in the ventral dura mater of unknown etiology. In our case, the etiology of the ventral dural defect was probably associated with the calcified thoracic disc extrusion.

Stromal vascular fraction isolated from lipo-aspirates using an automated processing system: bench and bed analysis.

The heterogeneous stromal vascular fraction (SVF), containing adipose-derived stem/progenitor cells (ASCs), can be easily isolated through enzymatic digestion of aspirated adipose tissue. In clinical settings, however, strict control of technical procedures according to standard operating procedures and validation of cell-processing conditions are required. Therefore, we evaluated the efficiency and reliability of an automated system for SVF isolation from adipose tissue. SVF cells, freshly isolated using the automated procedure, showed comparable number and viability to those from manual isolation. Flow cytometric analysis confirmed an SVF cell composition profile similar to that after manual isolation. In addition, the ASC yield after 1 week in culture was also not significantly different between the two groups. Our clinical study, in which SVF cells isolated with the automated system were transplanted with aspirated fat tissue for soft tissue augmentation/reconstruction in 42 patients, showed satisfactory outcomes with no serious side-effects. Taken together, our results suggested that the automated isolation system is as reliable a method as manual isolation and may also be useful in clinical settings. Automated isolation is expected to enable cell-based clinical trials in small facilities with an aseptic room, without the necessity of a good manufacturing practice-level cell processing area.

A new concept for classifying skull base defects for reconstructive surgery.

To classify the defects of the skull base, we present a new concept that is intuitive, simple to use, and consistent with subsequent reconstructive procedures. The centers of defects are determined in the anterior (I) or middle (II) skull base. The defects are classified as localized in the defect's center (Ia, IIa) or extended horizontally (Ib, IIb) or vertically (Ic, IIc) from the defect's center. Accompanying defects of the orbital contents and skin are indicated by "O" and "S," respectively. An algorithm for selecting subsequent reconstructive procedures was based on the classification. Using the new system, we retrospectively reclassified 90 skull base defects and examined how the defect classifications were related to the reconstructive flaps used and postoperative complications. All defects were reclassified with the new system without difficulty or omission. The mean correlation rate was high (88%) between the flaps indicated by the new classification and the flaps that had actually been used. The rate of postoperative complications tended to be higher with Ia, Ic, and IIb defects and combined defects. Our new classification concept can be used to classify defects and to help select flaps used for subsequent reconstructive procedures.

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.