George A. Sisson

Experimental hydroxyapatite cement cranioplasty.

Hydroxyapatite cement is a calcium phosphate-based material that when mixed with water forms a dense paste that sets within 15 minutes and isothermically converts in vivo to a microporous hydroxyapatite implant. This cement was used to reconstruct bilateral 2.5-cm-diameter full-thickness critical-sized parietal skull defects in six cats. One side was reconstructed with 100 percent hydroxyapatite cement, and the other with a mixture of 50 percent hydroxyapatite cement and 50 percent ground autogenous bone by weight. These animals were sacrificed at 6 and 12 months after implantation. Positive and negative controls also were prepared. The anatomic contour of the soft tissue overlying all hydroxyapatite cement implants was well maintained, there were no wound infections or structural failures, and the implants were well tolerated histologically. None of the negative (unreconstructed) control defects was completely filled with repair bone, and all positive (methyl methacrylate) controls demonstrated foreign-body giant-cell formation and fibrous encapsulation of the implants. Examination of decalcified and undecalcified sections revealed progressive but variable replacement of the cement by new bone and soft tissue without a change in the shape or volume of the hydroxyapatite cement-reconstructed areas. New bone comprised 77.3 and 64.7 percent of the tissue replacing the hydroxyapatite cement and hydroxyapatite cement-bone implants, respectively. Replacement of the hydroxyapatite cement implants by new bone is postulated to occur by a combination of osteoconduction and implant resorption. These results indicate that further experimental research leading to the possible application of hydroxyapatite cement for full-thickness calvarial defect reconstruction in humans is warranted.

Paranasal sinus malignancy: A comprehensive update†

A retrospective analysis of 60 cases of paranasal sinus cancer in patients admitted between 1970 and 1985 was undertaken. Forty‐six tumors originated in the maxillary sinus, and 14 originated in the ethmoid sinuses. Computed tomography, magnetic resonance imaging, and endoscopic sinus examination aided in early diagnosis of sinus cancer. Computed tomography aided in staging tumors; Caldwell‐Luc alone was inadequate for staging tumors invading deeper sites such as the orbits or pterygoid muscle. There were 15 early (T1 or T2) and 31 advanced (T3 or T4) maxillary sinus cancers. Multimodality therapy incorporated radiation, surgery, and chemotherapy. The 5‐year survival rate was 49%. We prefer preoperative radiotherapy for advanced lesions and postoperative radiotherapy for early lesions. The use of preoperative radiation therapy has increased our globe salvage rate. All but one of the patients who developed recurrent disease showed recurrence at the primary site prior to developing regional or distant metastasis. Radiation therapy, combined with aggressive surgical management to remove all tumor, provided the best survival rates in advanced lesions.

Endoscopic laser arytenoidectomy for the treatment of bilateral vocal cord paralysis

Most patients with bilateral vocal cord paralysis have a fairly satisfactory voice, but their airway is usually compromised. The management of such patients presents a challenge to the otolaryngologist‐head and neck surgeon. Numerous surgical procedures have been developed in an attempt to improve the patientss airway insufficiency without leaving him with a breathy, weak voice.

Endoscopic Management of Selected Early Vocal Cord Carcinoma

Twenty-five previously untreated patients with selected early midcordal squamous cell carcinomas have been treated by endoscopic excisional biopsy with the carbon dioxide laser and followed for a minimum of 3 years. Twenty-four of the 25 patients are alive and free of disease, and one patient died of local and regional recurrence 2 years after attempted endoscopic excision followed by partial laryngectomy. Indications, contraindications, advantages, and complications associated with this treatment option for patients with early glottic carcinoma are discussed.

Endoscopic Laser Arytenoidectomy Revisited

Arytenoidectomy is currently the most reliable method of treating patients with bilateral vocal cord paralysis. Although both endoscopic and external approaches have been described, the endoscopic laser technique is more desirable because it requires no incision and allows for the immediate assessment of airway size. Eleven patients with bilateral vocal cord paralysis treated by endoscopic laser arytenoidectomy were presented in 1984. At that time, 10 of the 11 patients had been successfully decannulated. Follow-up on that group of patients revealed that 7 of the 10 successfully treated patients remain decannulated with a good airway, although 2 of these patients required a revision procedure to excise a granuloma. One patient failed at 15 months and has failed two subsequent revision operations, and 2 patients have been lost to follow-up. Since 1984, 17 additional patients with bilateral vocal cord paralysis have been treated by the authors using the same endoscopic laser arytenoidectomy technique; all have been successfully managed, with a minimum follow-up of 3 years. The technique of this operation will be reviewed. This study demonstrates the clinical usefulness of endoscopic laser arytenoidectomy in the treatment of bilateral vocal cord paralysis.

Primary extracranial meningiomas of the head and neck.

Extracranial meningiomas comprise approximately 2% of all meningiomas. Primary extracranial meningiomas are even less common. This report details our experience with these unusual tumors from 1972 to 1989. The diagnosis, surgical management, and significant histopathologic features are discussed. The correlation of primary extracranial meningiomas with neurofibromatosis type II and a treatment algorithm are presented.

Transmandibular exposure of the skull base

The combined transmandibular-transcervical approach to the skull base ensures a wide field exposure to the lateral and midline compartments of the middle cranial fossa with attendant vascular control. Splitting the lip and mandible in the midline and dividing the floor of the mouth structures along the lateral border of the tongue exposes the parapharyngeal space, infratemporal fossa (lateral compartment), and clivus, nasopharynx, and cervical spine (midline compartment). A variety of benign and malignant intracranial and extracranial skull base lesions have been treated using this approach.

Tumors of the major salivary glands

Tumors of the major salivary glands are reviewed according to classification, location, surgical procedure and end results. Our data of the incidence of benign and malignant tumors show that the most commonly involved area is the parotid gland and the most frequent is of the mixed variety.

Modified tracheoesophageal diversion for chronic aspiration

Breakdown of the normal protective function of the larynx, either through primary laryngologic or neurologic causes, leads to chronic aspiration, recurrent pneumonitis and possibly death. In this paper we discuss the existing surgical treatments for chronic aspiration. Tracheal separation and trechcocsophageal diversion are discussed, as are the difficulties of using these procedures in patients with pre‐existing tracheostomies. A modification of trachcoesophageal diversion is presented whereby this procedure can now be utilized in those patients with pre‐existing tracheostomies. The modified tracheoesophageal diversion is performed in five patients successfully. Since most patients have already had tracheotomies in an attempt to control aspiration, we feel that our technique of modified trachcoesophageal diversion enables this group of patients to benefit from this procedure as well.

Immediate reconstruction after total laryngopharyngoesophagectomy and mediastinal dissection

Advanced or recurrent carcinoma surrounding the tracheostoma in a previously laryngectomized patient is most effectively treated with transsternal radical dissection of the upper mediastinum and relocation of the trachea to the upper chest. The use of the pectoralis major myocutaneous flap, now enables the head and neck surgeon to perform immediate reconstruction and provide protection for the great vessels after mcdiastinal dissection for stomal recurrence. Formerly, patients with stomal recurrence also involving the cervical or upper thoracic esophagus were poor surgical candidates. Frequently, patients succumbed to their disease before the continuity of the digestive tract could be re‐established.