Robotic endoscopic surgery of the skull base: a novel surgical approach

OBJECTIVE: To describe a novel robotic surgical approach that allows adequate endoscopic access for resection of tumors involving the anterior and central skull base and allows 2-handed, tremor-free, endoscopic dissection and precise suturing of dural defects. DESIGN: Transnasal endoscopic approaches are being increasingly used for surgical access and resection of tumors of the anterior and central skull base. One major disadvantage of this approach is the inability to provide watertight dural closure and reconstruction, which limits its safety and widespread adoption in surgery of intracranial skull base tumors. Other disadvantages include limited depth perception and several ergonomic constraints. Four human cadaver specimens were used for this study. The surgical approach starts with bilateral sublabial incisions and wide anterior maxillary antrostomies (Caldwell-Luc). Transantral access to the nasal cavity is gained through bilateral wide middle meatal antrostomies. A posterior nasal septectomy facilitates bilateral access by joining both nasal cavities into 1 surgical field. The da Vinci Surgical System is then "docked" by introducing the camera arm port through the nostril and the right and left surgical arm ports through the respective anterior and middle antrostomies, into the nasal cavity. A 5-mm dual-channel endoscope coupled with a dual charge-coupled device camera is inserted in the camera port and allows for 3-dimensional visualization of the surgical field at the surgeon's console. Using the robotic surgical arms, the surgeon may perform endoscopic anterior or posterior ethmoidectomy, sphenoidotomy, or resection of the middle or superior turbinates depending on the extent of needed surgical exposure. In addition, resection of the cribriform plate is performed robotically with sharp dissection of the skull base. The dural defect is then repaired with a 6-0 nylon suture. RESULTS: Adequate access to the anterior and central skull base, including the cribriform plate, fovea ethmoidalis, medial orbits, planum sphenoidale, sella turcica, suprasellar and parasellar regions, nasopharynx, pterygopalatine fossa, and clivus, was obtained in all cadaveric dissections. The 3-dimensional visualization obtained by the dual-channel endoscope at the surgeon's console provided excellent depth perception. The most significant advantage was the ability of the surgeon to perform 2-handed tremor-free endoscopic closure of dural defects. CONCLUSIONS: Transantral robotic surgery provides adequate endoscopic access to the anterior and central skull base. To our knowledge, this is the first study to report the feasibility and advantages of robotic-assisted endoscopic surgery of the skull base. This novel approach also allows for 3-dimensional, 2-handed, tremor-free endoscopic dissection and precise closure of dural defects. These advantages may expand the indications of minimally invasive endoscopic approaches to the skull base.     

Challenges in molecular imaging of Parkinson's disease: a brief overview

Positron emission tomography (PET) is a sensitive and specific non-invasive molecular imaging technique providing quantitative images and data on biochemical pathways, molecular interactions, drug pharmacokinetics and pharmacodynamics. The PET measurement of regional biochemical functions requires a rational design of the radiolabelled probes employed. When choosing a drug to radiolabel there are many considerations, the most important being the potential of the drug to provide the information that is required in vivo. For example, when developing a radiolabelled probe for measuring the regional concentration of a neurotransmitter receptor the affinity and selectivity of the drug need to be considered. Other factors which influence a decision about which drug to radiolabel include the ability of the drug to reach its target, drug lipophilicity and metabolism, toxicity and the amenability to radiolabelling. PET has been applied in studies of Parkinson's disease (PD) and has provided important information on disease on-set and progression. This brief overview aims to outline the challenges and capabilities of PET and the more commonly used molecular probes in PD studies.     

Maxillary osteosarcoma associated with a dental implant: report of a case and review of the literature regarding implant-related sarcomas

BACKGROUND: The development of malignant neoplasms has been reported as a rare complication of the use of implanted biomaterials. The majority of these cases have been sarcomas related to orthopedic hardware. The authors present the first reported case of a sarcoma arising in association with a dental implant. CASE DESCRIPTION: A 38-year-old woman developed a low-grade chondroblastic osteosarcoma of the right maxilla 11 months after receiving a titanium dental implant. She was treated with systemic chemotherapy and then a maxillary resection. As of this publication, 47 months later, she is alive and disease-free. CLINICAL IMPLICATIONS: The use of endosseous implants has been associated with a low risk for the development of cancer. As the use of dental implants continues to expand, dentists need to be aware of this rare but devastating complication.