Highly selective vagotomy using tantalum clips

A technique is described for performing highly selective vagotomy in cases of duodenal ulcer. Tantalum clips are used instead of conventional ligatures for securing the nerves and blood vessels that pass to the lesser curve of the stomach. With this technique the author has found the operation of highly selective vagotomy quicker and easier to perform.

Histopathological evaluation of materials implanted in the cerebral cortex

Histopathological changes of the cerebral cortex in response to small, penetrating metal and non-metal implants were analyzed by means of light and electron microscopy. The needle-shaped implants were left in place during all stages of histological preparation and embedded in plastic together with the cortex. Changes of the brain-implant boundary were classified as non-reactive, reactive, or toxic, according to the reactive cellular constituents. Among the non-reactive materials were several plastics and metals such as aluminum, gold, platinum, and tungsten. The boundary of these implants displayed little or no gliosis and normal neuropile with synapses within 5 micron of the implant's surface. The boundary of reactive materials such as tantalum or silicon dioxide was marked by multinucleate giant cells and a thin layer (10 micron)) of connective tissue. Toxic materials such as iron and copper were separated from the cortical neuropile by a capsule of cellular connective tissue and a zone of astrocytosis. Cobalt, a highly toxic material, produced more extensive changes in the zones of connective tissue and astrocytes. These results indicate that a variety of materials are well tolerated by the brain and could be used in the fabrication of neuroprosthetic devices.

Structural changes in the human vas deferens after tantalum clip occlusion and conventional vasectomy

In 15 human subjects, the vasa deferentia were occluded by applying two tantalum clips on one side and by conventional vasectomy with silk ligatures on the other. After 2 weeks, the occluded segments were recovered for histopathologic examination of serial sections. Obstructing the seminal tract did not, as such, produce any significant change in the vas: the distal and proximal segments appeared to be essentially similar and normal. At the actual site of occlusion, however, tantalum clips produced marked flattening of the tube, complete loss of lining epithelium, distortion of the muscular lamellae, and areas of hemorrhage. The lumen was converted into a narrow slit. Under the ligatures, the damage was largely confined to denudation of the mucosal epithelium. The mucosa of the intersegment left unexcised between two clips showed hyalinization, invasion by macrophages, and degeneration of the epithelium. The changes under the clips suggest that, although clip occlusion may offer several advantages, sterility cannot be reversed merely by removing the clips. The mechanisms of these changes, different in the case of clips and ligatures, are discussed and some possible long-term consequences are considered.

[Tantalum is contrast material for the better presentation of the ureter in retrograde pyelography (author's transl)]

Suspension of Tantalum dust can be used as contrast material. It helps in producing X-ray films which are rich in contrast and details. The composition of the suspension and the technique of retrograde pyelography with the suspension is described.

Maxillary growth after palatal surgery. An experimental study on dogs

Maxillary growth after unilateral closure of surgically induced defects in the hard palate in 6- to 8-week old Beagle puppies was studied. The hard palate except for a 4 mm wide strip of bone in the midline and with its overlaying oral mucoperiosteum was removed. On one side the nasal mucoperiosteum was covered with an autogenous full-thickness skin graft (side SGS) and, on the other side the raw surface (side RS) was left for secondary epithelialization. The animals were killed at 47 to 52 weeks of age. Measurements on the dried skulls of the experimental dogs showed no difference in total maxillary length between the two sides of the maxilla. However, the posterior half of the maxilla was longer in 8 dogs on side SGS and the anterior half of the maxilla was in 7 dogs long on side RS. The palatine suture was displaced towards side RS on all dogs, and the height of the nose was in all dogs greater on side SGS. There was a small consistent tendency that the overall growth was more pronounced on the side with the full-thickness skin graft. It is concluded that reducing the amount of scar tissue by covering raw surfaces with an autogenous full-thickness skin graft is one way to reduce maxillary growth impairment after palatal surgery.

Vas occlusion by tantalum clips and its comparison with conventional vasectomy in man: reliability, reversibility, and complications

Occlusion of the vas deferens has been carried out by applying tantalum clips in 60 men. Another 50 men were vasectomized conventionally and served as controls. Vasography showed that two clips were required on each vas to bring about perfect and firm occlusion. The incidence of postoperative infection and other complications was much lower in the clip-occluded cases. Under a long-term follow-up, 10% of the conventionally vasectomized men were dissatisfied with the operation as compared with 2% of the clip-occluded group. Both groups became azoospermic within 3 months and the failure rate was zero. Removal of the clips not only was difficult but left the vas compressed and leaking. The method cannot, therefore, be considered reversible by itself. However, recanalization could easily be achieved by end-to-end anastomosis after excision of the small clipped segment or by side-to-side anastomosis without any excision. This, damage to the neuromuscular apparatus of the vas may be minimized. Male sterilization by clip occlusion has the advantages of minimal surgical intervention, shorter operative time, safety from postoperative infection, and easier recanalization if desired.

Tantalum oxide and alveolar macrophage function

The alveolar macrophage (AM) has been cited as a potential source for clearing tantalum from the lungs following bronchography. We studied the short term effects of tantalum oxide on rabbit AM viability and metabolism in vitro. AM phagocytosed tantalum oxide particles without cytotoxicity and with a significant rise in glucoxe oxidation. These results suggest that the AM represents an important vehicle for clearance of tantalum particles from airways in vivo.

[Needle implantations--clinical report]

In the last four years 27 patients with edentulous lower jaw were treated with implantation of rows of tantalum needles; 25 of them were followed up clinically and radiologically. After an average of two years and seven months where the success rate was found to be 72%. Reasons for failure were thought to be mistakes in operative technique, insufficient oral hygiene of the patients and less than optimal aftercare. These needle implants have proved their value also in cases with marked atrophy of the lower jaw where other prosthetic-surgical methods aimed at improving the prosthesis site have failed.

Exposed cranial implants--a salvage operation

We present our rationale for attempting to cover some exposed cranial implants by tissue transfers. We have tried this in 9 patients, and we have had success in 5.

A study of methods for the determination of lead and cadmium

This paper describes laboratory comparisons of precision and accuracy of some widely used methods for the determination of lead in blood and for lead and cadmium on filters. With the exception of the tantalum boat atomic absorption technique, the methods studied were found to be rugged for a variety of minor procedural changes. Recovery of cadmium from spiked filters was quantitative over a wide range of dilutions and for a variety of instrumental readout and calculation combinations.

Grafting in dentistry today (author's transl)

Enossal grafts are common practice in dentistry. The prognosis of such grafts fluctuates between primary failure and 10 years, and is largely determined by the indication: the more accurate the indication, the better the prognosis! In partial diastemata in the lower jaw, satisfactory results for a longer time are to be expected if the concurrently blocked remaining denture is periodontally sound.

The changes produced by presurgical orthopedic treatment of bilateral cleft lip and palate

A serial cephalometric analysis (with the aid of metallic implants) and an analysis of the models of 10 children with complete bilateral clefts, who received presurgical orthopedic treatment, was done. It revealed that such therapy can successfully reduce the protrusive deformity of the premaxilla, when forward growth of this structure is restrained so as to allow the remainder of the face to "catch up." Our other observations include the accentuation of the columella during treatment, but an absence of growth at the cleft margins. Orthopedic treatment which fails to achieve the desired aims in 12 weeks of active therapy should be discontinued then in favor of such surgical setback as may be necessary to allow a satisfactory lip repair.

Viral lesions of the respiratory tract compared to iatrogenic trauma

A comparison between the mucosal pathology of the respiratory tract in cases of viral infections and of iatrogenic trauma after bronchoscopy and tantalum bronchography indicates that the respiratory mucosa has a very high degree of resistance against infection after trauma and is capable of rapid regeneration as long as the production of mucus continues and the surface remains moist. Viral infection might primarily inhibit mucus production and open the road to secondary infection.

High resolution shadowing for electron microscopy by sputter deposition

The sputtering process by an ion beam well collimated and highly accelerated provides a valuable means of high resolution shadowing, replication of a fine object by a combination of pre-shadowing and deposition as well as a preparation of supporting films. High resolution shadowing and films with grains smaller than 1 nm can be obtained by argon ion-sputtering targets of tungsten and tungsten/tantalum alloy. The resolution of carbon replicas pre-shadowed with tungsten/tantalum is determined from the radius of curvature of replicated magnesium oxide crystal corners.

Postoperative impairment of mucous transport in the lung

Impairment of mucous transport is considered significant to the postoperative development of atelectasis, but the association has never beed demonstrated in humans. Tantalum powder, which adheres to airway mucus, can be used to study mucociliary transport. The postoperative clearance of insufflated tantalum powder (mean diameter, 2.5 mum) was investigated in 25 patients. Eighteen patients underwent intra-abdominal vascular surgery and 7 undersent lower-extremity orthopedic procedures. At the completion of surgery, tantalum was insufflated into both lungs of each patient to outline a representative sample of airways from the trachea to the small bronchi. Tantalum clearance was evaluated from serial radiographs obtained immediately after insufflation, at approximately 6, 18, 26, and 48 hours later, and thereafter whenever appropriate. In the 7 orthopedic patients, clearance of tantalum was progressive and usually complete within 48 hours. Atelectasis did not occur in this group. In 14 of the 18 patients who had abdominal surgery, mucociliary clearance was markedly abnormal in that tantalum was retained for up to 6 days. Pooling of tantalum-labeled mucus occurred in dependent bronchi in 16 of these 18 patients. Pooling preceded and always accompanied radiographically visible atelectasis. Lobar atelectasis occurred in 6 patients and segmental atelectasis in 8. Tantalum-labeled mucus moved peripherally in atelectatic lobes or segments and was retained in these bronchi until re-expansion took place. Thus, impaired ciliary function and mucous transport are associated with and implicated in postoperative pulmonary atelectasis.

Effect of tantalum markers of longitudinal bone growth

Small tantalum pins (0.50 x 1.5 mm and 0.32 x 1.2 mm), used as intraosseous radio-opaque markers, were investigated for their effect on growth in 62 young rabbits. The tetracycline growth method was used and a difference in daily growth rate between the marked right leg and the unmarked left leg indicated a slight growth stimulation. The growth rate was slightly stimulated (at most, 26 mum/day) on days 1 and 2 after insertion, only if the larger markers were used. No growth effects were detectable on days 12 and 21.