Carcinomas of the ethmoid, frontal, or maxillary sinuses sometimes invade the anterior skull base. It is necessary to perform en-bloc resection for this invasive carcinoma according to the concepts of surgical treatment for head and neck cancer. The anterior skull base consists of two parts, the orbital roof as the lateral portion and the roofs of the frontal sinus, ethmoid sinus, and/or sphenoid sinus as the central portion. Selective reconstructive options for the anterior skull base depend on the size of the defect of the skull base. A dural defect is repaired by a fascia lata or a pericranial flap. After the dura has been tacked up, reconstruction of the anterior skull base is performed simultaneously with augmentation of the defect of extracranial structures. Larger defects that consist of both central and lateral portions with orbitomaxillary structures are reconstructed by a bulky musculocutaneous flap such as a rectus abdominis or latissimus dorsi flap. The bony reconstruction of supraorbital structures is also to be considered esthetically. On the other hand, intraorbital tissues are basically preserved in cases of central defects of the anterior skull base. These defects are reconstructed by a free forearm flap or a local flap such as a de-epithelialized midline forehead flap or a pericranial flap. We have selected and applied these flaps in 37 patients as reconstructive options for the anterior skull base since 1989. Eleven of the 37 patients had larger defects and 26 had central defects. De-epithelialized midline forehead flaps were used in 20 patients and were recognized to be a very useful and reliable reconstructive option for central defects of the anterior skull base.
Many approaches to the parapharyngeal space have been reported. However, few reports describe parapharyngeal space tumours and the best surgical approach to these tumours. We retrospectively examined the surgical approaches we used to resect 22 parapharyngeal space tumours. In order to determine the best surgical approach for each tumour, we first subdivided the parapharyngeal space into six compartments, based on anatomical landmarks seen on computed tomography and/or magnetic resonance imaging scans. We then determined the location of each tumour relative to these six parapharyngeal space compartments. In our series of cases, we found that large tumours spanning the superior portion of the parapharyngeal space could be completely removed through a skull base approach. To remove a large tumour in the middle and inferior portion of the parapharyngeal space, a transparotid approach was the most suitable. Finally, a tumour in the inferior portion of the parapharyngeal space was best accessed through a transcervical approach.
The choices for practical monitoring of free jejunal transfer have been quite limited because of its own characteristics, such as buried form, lack of skin surface, and the structure of a hollow viscous tract. Physiologically, it is known that tissue hypoxia caused by compromised perfusion leads to an increase of partial pressure of carbon dioxide (PCO2). Because of its physiological properties, the diffusion of carbon dioxide is always equilibrated between the mucosa of a hollow viscous organ and its lumen. The intramucosal PCO2 (PiCO2) of the gastrointestinal tract can therefore be determined indirectly from the intraluminal PCO2, which is measured with the aid of the tonometer catheter. To develop an optimal monitoring method for free jejunal transfer, the authors proposed the application of PiCO2 measurement by a modified use of a tonometer catheter. Since May of 1999, the authors performed postoperative PiCO2 monitoring on 20 cases of reconstructed pharyngoesophageal tracts in 18 patients who underwent radical tumor resection and one-stage reconstruction at the Shizuoka Red Cross Hospital. All 20 cases were safely monitored by PiCO2 measurement without any complications associated with the use of the tonometer catheter. In the 17 cases that succeeded uneventfully, the mean values of PiCO2 were kept lower than 40 mmHg throughout the monitoring period. On the other hand, the other three cases (15 percent) needed reexploration due to development of vascular complications, which was alerted by an abrupt increase of PiCO2 in each case (229, 130, and 99.6 mmHg). Two of the patients were fortunately successfully treated by immediate reexploration, leading to a 95 percent overall success rate. No false-negative or false-positive cases were observed. The authors' experience suggests that PiCO2 measurement using a tonometer catheter can provide the surgeon with reliable information for evaluating the perfusion and viability of a free jejunal transfer. Simplified manipulation and the objectivity of the numerical data allow stable measurement of PiCO2 and prompt judgment of the adequacy of the perfusion, which could minimize the burden and anxiety of the surgeon, particularly in the early postoperative period.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations鈥揷itations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.