Anatomical variations of the tympanic and mastoid portions of the facial nerve canal. A radioanatomical investigation.

PURPOSE: To obtain information on the morphology of the tympanic and mastoid portions of the facial nerve canal, and on the appearance of unusual vascular channels and anomalies such as dehiscences. MATERIAL AND METHODS: One hundred and two temporal bone preparations were examined by conventional radiography to evaluate mastoid pneumatization. Of these, 73 were examined by high resolution CT in order to test the ability of the method to detect dehiscences in the bony wall of the tympanic portion of the canal and the accompanying channels along its mastoid portion. Subsequently produced plastic preparations were used to measure the length and width of these 2 portions of the facial canal. RESULTS: Our study reports observations on the three-dimensional morphology of the canal in the plastic casts. The study shows variations in the course and dehiscences of the tympanic portion. Additional bony channels along the mastoid portion are described. These results supplement those in previous investigations. CONCLUSION: The measurement results agree with those of previous investigations. The course of the tympanic portion is S-shaped and has an impression on its upper surface. High resolution CT reproduces dehiscences of the bony canal in a percentage similar to that of microscopical methods and in relevant sites. Pneumatization does not influence the dimensions of the 2 portions.

Frequency of proximal tubal obstruction in patients undergoing infertility evaluation.

Fallopian tube recanalization is a technique for treatment of proximal tubal obstruction caused by debris. The true frequency of infertile women for whom this treatment is suitable is not well known. In this study all hysterosalpingograms (HSGs) performed over a 3-year period (1986-88) were reviewed. The HSGs were performed as part of an infertility evaluation program in 494 women, with a mean duration of infertility of 2.4 years. Bilateral proximal tubal obstruction was found in 3% and unilateral proximal obstruction in 2% of the cases. In women examined in the first 2 years (1986-87) (n = 328), the birth frequency after HSG was 25%. When HSG was performed with optimal technique the number of patients who were suitable for Fallopian tube recanalization was low.

Anatomic variations of the chorda tympani canal.

The anatomic variations of the facial recess are of interest in certain otosurgical procedures. The medial border of the recess is the mastoid portion of the facial nerve canal, and the lateral border is the bony canal of the chorda tympani. These two structures were investigated in 64 polyester casts of temporal bone specimens. The point of exit of the chorda tympani canal from the facial canal was assessed together with the angle, formed between these two nerve channels. As a further way of describing the spaciousness at the facial recess, the distance between the sulcus of the stapedius muscle and the chorda tympani canal was evaluated.

The cochlea and the carotid canal.

The carotid canal conveys a large artery and lies in close topographic relationship to the basal turn of the cochlea. The bony wall between them consists in some cases only of the petrous bone of the otic capsule. It can be as thin as 0.2 mm. In other cases the distance can be more than 6 mm. A systematic assessment of the relationship between these two structures was performed on plastic casts of 173 human temporal bone specimens in order to investigate the range of normal variation. The topography in this region can be visualized by multidirectional tomography or CT.

Angiographic findings and need for amputation in high tension electrical injuries.

Because it is difficult to estimate the extent of deep tissue injury clinically, angiography was carried out in 28 patients with signs of damage from current flow through the body. Eight of the arteriograms showed normal extremities, 6 showed changes of small arteries, and 38 showed injury to the main arteries. In the latter group there were 24 total arterial occlusions, narrow irregular lumens in 10, and 4 had occlusion and distal refilling. Changes in the main arteries were most often seen near major joints where the internal body resistance as well as the density of the current are higher. Injury to the main arteries resulted in severe neuromuscular damage or amputation of the limb, whereas injury to small arteries resulted in little functional deficit. Of the 25 amputations 19 were at the level of the arterial occlusion. Spasmolytic drugs did not increase filling. We conclude that early angiography is valuable for the detection of deep injury and often indicates the level of adequate amputation or the need for immediate exploration. In some patients it indicates the necessity for arterial reconstruction.

Repair of the triangular ligament in Colles' fracture. No effect in a prospective randomized study.

We present a prospective and randomized study of two different treatments of extraarticular Colles' fracture with a fractured ulnar styloid. The study comprised 41 patients with 2 years' follow-up; 22 patients were treated with closed manipulation and an above-the-elbow plaster cast, whereas in 19 patients the avulsed ulnar styloid was transfixed and/or the triangular ligament was repaired after closed reduction of the fractured radius. In all the operated on patients, a complete rupture of the triangular ligament was found. Good reduction of all the fractures was achieved primarily according to the radiographic examination. At follow-up the alignment had deteriorated, with no difference between the two treatment groups. Neither did the findings in the wrist arthrograms differ between the two groups nor did the subjective complaints of the patients. We conclude that repair of the ruptured triangular ligament in extraarticular fractures of the distal radius is not better than conventional treatment.

Triscaphoid arthrodesis and its complications.

Carpal instability and/or arthrosis of the scaphotrapezial joint were treated with scaphotrapezio-trapezoid arthrodesis in 19 hands. Healing failed primarily in five hands as determined by conventional or computed tomography. No correlation was found to surgical methods or immobilization time. Surgical revision had to be done for four of the nonunions. These complications do not correspond to those described in the literature but draw attention to some adversities encountered in the use of this method.

Imaging contributions to the temporal bone anatomy (high jugular fossae).

A high jugular fossa, above the lower border of the round window, sometimes with a diverticulum-like protrusion from the top, was found in 23% of an unselected material, usually associated with low pneumatization. They were more common in the right than the left temporal bone. The high jugular fossa has a varying anatomy and its topographic relationship has been evaluated. The laterally situated fossa could be dehiscent to the tympanic cavity and intrude upon the round window or the ossicles. The high, medial fossa encroached in some cases upon structures in the inner ear, such as the vestibule, the cochlear and vestibular aqueducts, the posterior semicircular canal, the cochlea or the mastoid portion of the facial canal and this was considered in relation to the symptoms in a clinical material.

The labyrinthine portion of the facial canal. A comparative radioanatomic investigation.

The variational radiographic anatomy of the labyrinthine portion of the facial canal was investigated in 200 plastic and silicone casts of unselected temporal bone specimens by means of multidirectional and computed tomography in different projections. The labyrinthine portion of the canal varied considerably in shape and size; in some specimens the cross-section was circular, but often the canal was crumpled and flattened in its passage above the cochlea. The medial part of the labyrinthine portion was narrowest, the lowest cross-sectional area being 0.5 mm2. In spite of optimal positioning of the specimen it was not always possible to reproduce the entire labyrinthine portion of the canal completely. Most difficult to reproduce were specimens with extremely small vertical diameters and marked caudal sloping of the canal.

The labyrinthine portion of the facial canal in patients with Bell's palsy investigated by computed tomography.

The reproducibility of the labyrinthine portion of the facial canal by computed tomography was investigated in 22 patients with Bell's palsy. The CT images were compared with those obtained in 18 temporal bone specimens. Measurements of the diameters of different parts of the facial canal were made on these images and also microscopically in plastic casts of the temporal bone specimens. No marked difference was found between the dimensions of the labyrinthine portion of the facial canal of the involved and healthy temporal bone in the patient, nor did these differ from the dimensions in the specimens. CT of the slender, curved labyrinthine portion was found to be of doubtful value for metric estimation of small differences in width. The anatomic variations of the canal rendered the evaluation more difficult. CT with a slice thickness of 2 mm was of no value for assessment of this part of the canal. Measurement of the diameters of the labyrinthine portion on CT images is an inappropriate and unreliable method for clinical purposes.

Effects of a high jugular fossa and jugular bulb diverticulum on the inner ear. A clinical and radiologic investigation.

From a series of patients undergoing routine radiographic examination, 112 temporal bones with a high jugular fossa were selected. Among these, 43 jugular bulb diverticula were found. The structures affected by a high fossa or diverticulum were recorded and correlated to the clinical symptoms of the patient. The vestibule was suspected to be affected in five patients. Two of these patients had tinnitus and vertigo, and three had hearing loss. In one of the latter the hearing loss was most marked in the supine position. The cochlea was close to the fossa in three patients, all of whom had tinnitus. Four patients had a defect of the posterior semicircular canal. One of them lost his hearing after a severe fit of coughing, became unsteady and showed signs of a fistula. The internal acoustic meatus and the mastoid portion of the facial canal were affected in two and four patients, respectively, who had no recorded symptoms. Twelve of 34 patients with Menière's disease and a high jugular fossa on the side of the diseased ear had a dehiscence of the vestibular aqueduct caused by the fossa or diverticulum, compared with nine of 58 patients in the unselected material. For comparison and demonstration of topographic relationships, 58 casts of unselected radiographed temporal bone specimens with high jugular fossae or diverticula were investigated. In patients with a high jugular fossa or jugular bulb diverticulum, tomographic assessment may be of value.

The jugular bulb diverticulum. A radioanatomic investigation.

Two hundred and forty-five temporal bone specimens were examined radiographically. Subsequently the topographic relationship between the jugular fossa and surrounding structures was evaluated in plastic casts of the specimens. Fifty-eight casts showed a high jugular fossa and in 17 a jugular bulb diverticulum was found. A diverticulum is regarded as an anomaly of the high jugular bulb and presumably has a potential for expansion. Most frequently a diverticulum was directed medially into the space between the internal acoustic meatus, the vestibular aqueduct and the posterior cranial fossa. Seven diverticula reached the level of the internal acoustic meatus. Encroachment upon the vestibular aqueduct was seen in 4 casts and both the internal acoustic meatus and the cochlear aqueduct were very close to the diverticulum. A few diverticula were directed postero-laterally close to the facial canal and the stapedius muscle. The investigation was supplemented with a selected clinical material of radiographs of temporal bones with high fossae. The results corresponded to those of the experimental investigation. The jugular bulb diverticulum is a relatively common feature and should be regarded as an anomaly with a potential to give rise to clinical symptoms consequent to its intrusion upon surrounding structures.

The topographic relations of the high jugular fossa to the inner ear. A radioanatomic investigation.

The radioanatomy of high jugular fossae and their topographic relations to the inner ear structures were investigated in 245 unselected temporal bones. One hundred and fifty specimens were submitted to multidirectional and 10 to computed tomography. After careful chemical and fermentative maceration plastic casts were made, using polyester resin and silicone rubber. With the use of vacuum, even minute structures became filled with the casting material. The specimens offered a three-dimensional view of the jugular fossae and surrounding structures. Fifty-eight (24%) of the total 245 specimens had high jugular fossae at a level above the lower border of the round window. Five casts showed a dehiscence of the peripheral portion of the vestibular aqueduct caused by the high jugular fossa. In 2 casts the proximal portion of the cochlear aqueduct was affected. In some casts the posterior semicircular canal, the facial canal, the stapedial muscle and the round window lay so close to the fossa that a dehiscence could not be excluded. In a clinical material of 102 high fossae the radiographic findings were in accordance with the experimental results. High jugular fossae were predominantly found in pyramids with low-grade mastoid bone pneumatization and sparse or no perilabyrinthine air cells.

Results from resection of the distal end of the ulna after fractures of the lower end of the radius.

Pain, impaired mobility and weakness in the wrist are common complications after fractures of the lower end of the radius. When these symptoms persist, resection of the distal end of the ulna has been the surgical treatment of choice. 24 patients who had undergone this procedure were reviewed. 50% stated they were not improved by the operation. Of 11 patients with degenerative changes in the distal radio-ulnar joint on preoperative X-ray, 8 stated they were helped by the operation, while of 13 patients without any signs of arthrosis in the distal radio-ulnar joint, only 4 experienced relief of their discomfort. A more discriminating approach to the treatment of the sequelae of fractures to the lower end of the radius is required. Resection of the distal end of the ulna is probably only indicated when the distal radio-ulnar joint shows sings of arthrosis.

Gastric emptying in duodenal ulcer patients before and after truncal vagotomy with pyloroplasty and parietal cell vagotomy.

The gastric emptying of a liquid test meal containing 99Tcm-sulphur colloid was studied with a gamma camera in 24 duodenal ulcer patients. Studies were made before surgery, randomly chosen between truncal vagotomy with pyloroplasty and parietal cell vagotomy, and six weeks and one year after. Large variations in the emptying patterns were observed both between patients and in the same patients. No consistent change in the distribution of patterns were found between the three observation times and between the two surgical procedures. An initial rapid emptying was found in several studies and was observed both before and after operation and did not seem to be related to type of surgical procedure or to individual patients. The method applied did not allow a detailed study of this initial phase, which appears to be of a higher significance for the over-all emptying characteristics than the late exponential emptying, on which earlier investigators have been focused.