Observation of tumour thickness and resection margin at surgical excision of primary oral squamous cell carcinoma--assessment by ultrasound.

Tumour thickness and the status of resection margins are of prognostic significance in the treatment of oral cancer. In a single blind prospective study, 14 patients with biopsy proven oral squamous cell carcinoma had intraoral ultrasound imaging done preoperatively to measure tumour thickness, and intraoperatively to measure the deep surgical margin half way during resection. The cut surface was demonstrated on ultrasound by placing a metal, ultrasound-reflective, retractor into the surgical cut. The ultrasound measurements were compared to the subsequent histological measurements. Using the threshold of 5mm as indicator of margin clearance, there was agreement in 10 out of 14 cases between ultrasound and histology. Ultrasound detection of close surgical margins had a sensitivity of 83% and a specificity of 63%. For preoperative tumour thickness measurement, ultrasound imaging showed a high degree of correlation with histology (Pearson correlation coefficient=0.95, P<0.01). This original paper demonstrates that high resolution ultrasound imaging applied intraorally is a reliable tool in objectively assessing both the tumour thickness and the surgical margin clearance at the time of surgery.

A new approach using intraoperative ultrasound imaging for the localization and removal of multiple foreign bodies in the neck.

An innovative method of using ultrasound imaging intraoperatively is reported. Multiple radiopaque and radiolucent foreign bodies within soft tissues were localized in theatre using high resolution ultrasonography. Depth of injury and vessel status were also ultrasonically assessed. Surgical removal of all foreign bodies was aided by intraoperative ultrasound guidance. In addition, this new approach of using intraoperative ultrasonography was pivotal in confirming the removal of all foreign bodies from the wound at the time of the operation.

Intraoperative ultrasound imaging to aid abscess drainage--a technical note.

Diagnostic ultrasound is used widely to identify the presence of fluid collections preoperatively. Although its role in other parts of the body is well established, this report describes the technique of using diagnostic ultrasound intraoperatively to aid drainage of a large fascial space abscess in the head and neck. Following previously inadequate drainage of a large superficial abscess from a blindly placed drain, a second procedure was carried out, using ultrasound imaging to locate the persisting abscess. Furthermore, ultrasound demonstrated the adequacy of drainage and helped the surgeon to position the drain in the correct tissue space. We consider that intraoperative use of ultrasound has a role as a guidance tool to drain superficial fascial space abscesses in the head and neck region.

Intraoperative ultrasound-guided retrieval of an airgun pellet from the tongue: a case report.

Real-time intraoperative ultrasonography was used to detect and facilitate removal of an airgun pellet from the tongue of a 14-year-old boy. Diagnostic ultrasound was crucial in clarifying the positional relation between the foreign body and the instrument used, enabling safe, precise and rapid retrieval during a potentially hazardous surgical operation.

Intermaxillary fixation is not usually necessary to reduce mandibular fractures.

We undertook a retrospective study of all isolated mandibular fractures which had required active management over a 1-year period at the Maxillofacial Unit at Newcastle General Hospital. Patients with single or multiple fractures of the mandible were included in the study, if there were other simultaneous fractures of the facial skeleton, those patients were excluded. All case notes and radiographs were reviewed by a single operator. A total of 202 cases of fractured mandible were identified of which 115 fulfilled the selection criteria of: isolated fracture, no previous facial fracture, treatment by open reduction and internal fixation using titanium osteosynthesis miniplates, and all case notes and radiographs available to study. Sixty-six patients had their fractures reduced manually to obtain anatomical reduction without the use of peroperative intermaxillary fixation (IMF). Forty-nine were treated conventionally using peroperative IMF. The two groups were broadly similar in severity and type of fracture, and the method of reduction seemed to be decided by the operator according to their preference. IMF was not used routinely postoperatively. Overall there were significantly fewer occlusal discrepancies in the early postoperative period in those patients treated by anatomical reduction (6/66 compared with 16/49, P = 0.002) but there was no difference in the final outcome of the occlusion between the two methods of reduction. Avoidance of the use of peroperative IMF is more economical in time and cost, is safer for the operator, and more comfortable for the patient. As this technique produces comparable results in the long term with fewer early complications, we conclude that IMF is not usually necessary to reduce fractures confined to the mandibular bone.

Post-extraction bleeding--an aid to diagnosis? Case report.

Haemophilia A, the most common of bleeding disorders is characterized by bruising and spontaneous bleeding into the joints but may remain undiagnosed if present in the mild form. A case is discussed where episodes of bruising and joint swelling as a child were misdiagnosed as rheumatic fever and the bleeding disorder was diagnosed following recurrent episodes of bleeding after extraction of an upper molar tooth.

Influence of aminooxyacetic acid on the potassium-evoked release of [3H]gamma-aminobutyric acid from slices of rat cerebral cortex.

The release of [3H]GABA from superfused slices of rat cerebral cortex was investigated in the presence and absence of the GABA-transaminase inhibitor aminooxyacetic acid (AOAA). In the latter case, an ion-exchange column chromatographic technique was used to separate [3H]GABA from tritiated metabolites released with it into the superfusate. In the absence of AOAA, omission of Ca2+ from the superfusion medium reduced the release of [3H]GABA evoked by a 30 mM K+ pulse by 81.6%, whereas in comparable experiments carried out in the presence of AOAA omission of Ca2+ reduced the K+-evoked release by only 23.5%. Similar results were obtained when a 50 mM K+ pulse was used, whereupon omission of Ca2+ reduced [3H]GABA release by 78.7% in the absence of AOAA as compared with a reduction of only 47.9% when AOAA was present. It is concluded that the presence of AOAA decreases the Ca2+-dependence of K+-evoked [3H]GABA release in this system.