Extended transbasal approach: anatomy, technique, and indications

Appropriate indications for the transbasal approach have not been clearly established. The focus of this study is to determine the feasibility of maximal exposure of the clivus and surrounding regions via this strategy. Further, we sought to determine the key anatomical landmarks and morphometric data necessary for safe, radical exposure. In 20 injected cadaveric specimens, anatomical observations were made grossly and microscopically with 4-40 x magnification. The three basic variations of the transbasal craniotomy were compared with regard to surgical exposure. Maximum exposure of the ventral clivus could be obtained by total ethmoidectomy and sphenoidectomy through the extensive transbasal craniotomy. The lateral limits of exposure were found to be the optic nerves, intracavernous carotid arteries, and hypoglossal canals. Inferiorly, the foramen magnum is the limit of exposure. Morphometric measurements were determined between the key landmarks and were found helpful in subsequent dissections due to the lack of bony structures in relation to neural and vascular structures within the bone. The keys to optimizing the transbasal approach are beyond the simple initial steps of the craniotomy. Maximal exposure from the suprasellar compartment to the foramen magnum is possible via the extended transbasal approach.     

A lateral transzygomatic-transtemporal approach to the infratemporal fossa: technical note for mobilization of the second and third branches of the trigeminal nerve

This report describes an alternative approach to the infratemporal fossa lesions through a lateral zygomato-temporal craniotemy, which modifies the extradural temporopolar technique for cavernous sinus surgery. First, an L-shaped osteotomy of the zygoma from the frontozygomatic suture attaching the zygomatre arch and low positioned temporal cramotomy are made. Through this zygomato-temporal craniotomy and orbitotemporal drilling, leaving the lateral orbital rim and orbital roof intact, skeletonization of the foramens rotundum and ovale are carried out. The key element of this infratemporal exposure is the dissection and mobilization of the trigeminal nerve, trigeminal second branch rostrally, and the third branch caudally, which facilitates a wide exposure of the infratemporal fossa with preserving trigeminal function. The corridor between the mobilized trigeminal branches provides direct access to the lateral and medial pterygoid plate, internal maxillary artery, sphenoid and maxillary sinuses, maxilla and, finally, the parapharyngeal area. Our experiences have demonstrated that this lateral transzygomatic-transtemporal exposure is satisfactory for use with infratemporal fossa tumors. This approach has an advantage for cranial-base exposure with decreased risks of cosmetic deformity and of trigeminal nerve dysfunction.     

Influence of the scan time point when assessing hypoxia in 18F-fluoromisonidazole PET: 2 vs. 4 h

European Journal of Nuclear Medicine and Molecular Imaging - 18F-fluoromisonidazole (18F-FMISO) is the most widely used positron emission tomography (PET) tracer for imaging tumor hypoxia. Previous...     

Type 1 collagen as a potential niche component for CD133‐positive glioblastoma cells

Cancer stem cells are thought to be closely related to tumor progression and recurrence, making them attractive therapeutic targets. Stem cells of various tissues exist within niches maintaining their stemness. Glioblastoma stem cells (GSCs) are located at tumor capillaries and the perivascular niche, which are considered to have an important role in maintaining GSCs. There were some extracellular matrices (ECM) on the perivascular connective tissue, including type 1 collagen. We here evaluated whether type 1 collagen has a potential niche for GSCs. Imunohistochemical staining of type 1 collagen and CD133, one of the GSCs markers, on glioblastoma (GBM) tissues showed CD133‐positive cells were located in immediate proximity to type 1 collagen around tumor vessels. We cultured human GBM cell lines, U87MG and GBM cells obtained from fresh surgical tissues, T472 and T555, with serum‐containing medium (SCM) or serum‐free medium with some growth factors (SFM) and in non‐coated (Non‐coat) or type 1 collagen‐coated plates (Col). The RNA expression levels of CD133 and Nestin as stem cell markers in each condition were examined. The Col condition not only with SFM but SCM made GBM cells more enhanced in RNA expression of CD133, compared to Non‐coat/SCM. Semi‐quantitative measurement of CD133‐positive cells by immunocytochemistry showed a statistically significant increase of CD133‐positive cells in Col/SFM. In addition, T472 cell line cultured in the Col/SFM had capabilities of sphere formation and tumorigenesis. Type 1 collagen was found in the perivascular area and showed a possibility to maintain GSCs. These findings suggest that type 1 collagen could be one important niche component for CD133‐positive GSCs and maintain GSCs in adherent culture.     

Basilar trunk aneurysm surgically treated with anterior petrosectomy and external carotid artery-to-posterior cerebral artery bypass: technical note

OBJECTIVE: We discuss a detailed surgical technique, its indications, and potential pitfalls in its use. METHODS: A surgical procedure combining Kawase's anterior petrosectomy and external carotid artery-to-posterior cerebral artery high-flow bypass was performed for the treatment of a patient with a fusiform basilar trunk aneurysm. RESULTS: Follow-up angiography revealed the successful obliteration of the aneurysm and that the graft was functioning well. Late ischemic complications, however, occurred 5 weeks after surgery. CONCLUSION: Kawase's approach is a versatile option for safe vascular reconstruction of the posterior cerebral artery and exposure of a basilar trunk aneurysm in the upper clival region. Although, theoretically, a high-flow bypass might decrease the risk of hemodynamic ischemia, it does not prevent thromboembolic complications.     

Vascular reconstructive surgery for elderly patients with internal carotid artery stenosis at the cervical portion

PURPOSE: We encounted increasing numbers of elderly patients suffering from stenotic lesions of the cervical internal carotid artery. Most of them have been considered to indicate a need for carotid artery stenting. The purpose of this study was to clarify with regard to the modality of treatment and perioperative complications the effectiveness of vascular reconstruction procedure in elderly patients. PATIENTS AND METHODS: Ninety eight lesions in 91 patients with stenosis of the internal carotid artery were treated surgically. Eighty lesions received carotid endarterectomy (CEA), and 18 lesions received percutaneous transluminal angioplasty (PTA) with or without stent. Treatment with PTA-with-or-without-stent has been opted in cases of patient with such conditions as radiation-induced stenosis, re-stenosis after CEA, unfitness for general anesthesia, bilateral lesions both of which need to be reconstructed with in a short interval. We divided the patients into 4 groups according to their age; under 70-year-old group, 70-to-74-year old group, 75-to-79-year old group, and over 80-year-old group. Vasoreconstructive procedures were performed for 41 patients in the under 70-year-old group, for 31 in the 70-to-74-year old group, for 21 in the 75-to-79-year old group, and for 5 in the over 80-year-old group. RESULT: The overall surgical morbidity rate was 2% (2 of 98 cases) and there was no mortality. Tweleve patients (12.2%) experienced transient neurological deficits. Two patients exhibited perioperative complications in gastrointestinal organs, but none of the patients experienced cardiac complications. Elderly patients tend to experience systemic complications such as gastrointestinal complications as well as transient neurological deficits, which appear as restlessness, possibly due to hyperperfusion syndrome. The perioperative complication rate in elderly patients (putting the patients of the 70-to-74-year old group, the 75-to-79-year old group, and the over 80-year-old group together) was, statistically, significantly higher than those in patients of under the 70-year-old group. However, when two treatment modalities, CEA and PTA-with-or-without stent, were compared, there was no significant difference in the perioperative complication rate. CONCLUSION: Careful patient selection and prudent perioperative management enabled us to perform vasoreconstructive surgery even for elderly patients with internal carotid artery stenosis in a relatively safe manner with an acceptable complication rate. Decision making in selecting treatment modality, CEA or PTA with or without stent, should not be based solely on aging.     

Structure-based design and synthesis of non-nucleoside, potent, and orally bioavailable adenosine deaminase inhibitors

We disclose optimization efforts based on the novel non-nucleoside adenosine deaminase (ADA) inhibitor, 4 (K(i) = 680 nM). Structure-based drug design utilizing the crystal structure of the 4/ADA complex led to discovery of 5 (K(i) = 11 nM, BA = 30% in rats). Furthermore, from metabolic considerations, we discovered two inhibitors with improved oral bioavailability [6 (K(i) = 13 nM, BA = 44%) and 7 (K(i) = 9.8 nM, BA = 42%)]. 6 demonstrated in vivo efficacy in models of inflammation and lymphoma.     

Completion radical surgery after cholecystectomy for accidentally undiagnosed gallbladder carcinoma

Abstract Survival time of 73 patients with undiagnosed gallbladder carcinoma incidentally found after cholecystectomy treated between 1982 and 2000 was evaluated in relation to various variables, with special reference to the significance of the radical second resection. The most significant prognostic factor was the depth of tumor invasion as assessed by univariate and multivariate analyses (odds ratio 3.40, 95% CI 1.65–7.00, p < 0.001). None of the 23 pT1 patients received radical second resection, and all of them were doing well without recurrence at their last follow-up examination. The 3-year survival rate was 68% for patients with pT2 and 14% for patients with pT3. Patient characteristics for the 18 pT2 patients who underwent radical second resection were similar to the characteristics of the 25 pT2 patients who did not; nor did postoperative survival times differ significantly. Survival time was not correlated with the interval from initial to second surgery or the type of initial cholecystectomy (open vs laparoscopic). In 11 patients with pT2 whose surgical margin was judged positive at initial cholecystectomy, the radical second resection significantly lengthened survival time. Radical second resection tended to prolong the median survival period from 7 to 15 months in 7 patients with pT3, although the difference was not significant. In conclusion, patients with pT1 undiagnosed carcinoma need no further treatment. The redo surgery was found to prolong survival only in patients with pT2 with positive surgical margin at initial cholecystectomy. Electronic Publication