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PubMed2002

[Systematic circumferential (360 degree) decompression treatment of major arthrotic cervical stenosis].

PURPOSE OF THE STUDY: Worsening and irreducible evolution of neural involvement in cervical stenosis requires cord decompression. Different techniques have been proposed. We associated a dual posterior then anterior approach to achieve 360 degrees decompression. We evaluated results on the basis of neurological and mechanical outcome. MATERIAL AND METHODS: Twenty-eight patients, 16 men and 12 women, mean age 60.2 years (range 40-82) underwent surgery between 1989 and 1999 for severe cervical canal stenosis. Patients were referred for neurological symptoms: 20 for radicular symptoms (8 pain, 11 motor deficit, 12 sensitive deficit). Fifteen patients presented myelopathic symptoms. Pyramidal syndrome in 11 and tetraparesia in 3. Neurological involvement was scored according to Nurick (average 1.74) and JOA (average 12.6). Pain was scored on the Robinson scale. Levels to decompress were identified on static and dynamic plain x-rays, CT scans and MRI. Myelography was rarely used (first case only). MRI demonstrated preoperative myelomalacia in 5 patients and syringomyelia in 2. The surgical technique for 360 degrees fusion involved two steps, performed with a 1-week interval for 12 patients and during the same procedure for the others. The first approach was posterior enabling spine fixation with bilateral Roy-Camille plates and decompression by laminectomy using the lobster shell technique. The anterior approach consisted in corpectomy with the Simmons technique (22 cases or multilevel interbody fusion according to Robinson. Iliac bone grafting was used in all but one patient who had a fibular bone graft. Mean follow-up was 18.5 months (6-78). RESULTS: Neurological improvement was 1.74 to 0.92 on the Nurick sclae and from 12.6 to 15.2 on the JOA scale at last follow-up. Fusion was obtained in all cases. There were 2 cases of neurological worsening and one transient dysphagia. Operative bleeding for the two steps was 700 ml (150 ml for the posterior procedure and 400 ml for the anterior procedure). CONCLUSION: 360 degrees arthrodesis for severe cervical canal stenosis provides a satisfactory solution to mechanical problems and substantial neurological improvement. Fusion is regularly obtained without complementary anterior instrumentation. Neurological improvement is correlated with disease duration and the degree of deficit at onset. Anteroposterior decompression and 360 degrees fusion provide cure for all the components of stenotic disease. The dual approach is indicated in severe cases with cord involvement as recognized by myleopathic clinical manifestations and on the MRI.

Adult↗
PubMed1992

Intravascular bubble composition in guinea pigs: a possible explanation for differences in decompression risk among different gases.

Differences in risk of decompression sickness (DCS) that have been observed among inert gases may reflect differences in gas solubility or diffusivity or both. A higher risk gas might generate a larger volume of evolved gas during decompression, thereby increasing the probability of DCS. If this hypothesis is correct, the composition of bubbles that develop during decompression should reflect such gas differences. Unanesthetized guinea pigs were compressed to depths ranging from 250 to 350 fsw with air, He-O2 (21% O2) or one of a number of N2-He-O2 or N2-Ar-O2 mixtures (21% O2). Animals were held at depth from 15 to 60 min, then decompressed slowly (60 fsw/min) or rapidly (less than 15 s) to 5 fsw. If severe DCS developed, as judged by changes in physiologic variables, death usually occurred quickly. Gas/blood samples were then immediately withdrawn from the right atrium or the inferior vena cava, and the gas phase analyzed for He, N2, Ar, O2, and CO2 via gas chromatography. Bubbles from all dives contained 5-9% CO2, 1-4% O2, with the balance inert gas. Bubbles after N2-He-O2 dives contained substantially more N2 than He (up to 1.9 times more) compared to the dive mixture; bubbles after N2-Ar-O2 dives contained more Ar than N2 (up to 1.8 times more). For N2-He-O2 dives, the actual inert gas makeup of bubbles was dependent on the time-at-depth and the decompression profile. Results may reflect differences among He, N2, and Ar in tissue solubility/diffusivity and gas exchange rates, and support the rank order of increasing DCS risk (He less than N2 less than Ar) and rate of gas exchange (N2 less than He) observed previously during rat dives.

Animals↗
PubMed2004

Endoscopic orbital decompression for Graves' ophthalmopathy.

BACKGROUND: In patients with Graves' ophthalmopathy, orbital decompression surgery is indicated for compressive optic neuropathy, severe corneal exposure, or for cosmetic deformity due to proptosis. Traditionally this has been performed through a transantral approach, but the associated complication rate is high. More recently, endoscopic orbital decompression has been performed successfully with significantly fewer postoperative complications. OBJECTIVE: To report our experience of endoscopic orbital decompression in patients with severe Graves' ophthalmopathy. METHODS: Three patients (five eyes) underwent endoscopic orbital decompression for Graves' ophthalmopathy at Soroka Medical Center between the years 2000 and 2002. The indications for surgery were compressive optic neuropathy in three eyes, severe corneal exposure in one eye, and severe proptosis not cosmetically acceptable for the patient in one case. An intranasal endoscopic approach with the removal of the medial orbital wall and medial part of the floor was performed. RESULTS: In all five eyes an average reduction of 5 mm in proptosis was achieved. Soon after surgery, visual acuity improved in the three cases with compressive optic neuropathy, and exposure keratopathy and cosmetic appearance also improved. The diplopia remained unchanged. No complications were observed postoperatively. CONCLUSIONS: Endoscopic orbital decompression with removal of the medial orbital wall and medial part of the floor in the five reported eyes was an effective and safe procedure for treatment of severe Graves' ophthalmopathy. A close collaboration between ophthalmologists and otorhinolaryngologists skilled in endoscopic sinus surgery is crucial for the correct management of these patients.

Adult↗
PubMed2004

[Nerve exploration and decompression for traumatic recurrent laryngeal nerve injuries induced by thyroid gland surgery].

OBJECTIVE: To show the findings of recurrent laryngeal nerve injury exploration and find out therapeutic effects, indications and timing of nerve decompression for traumatic recurrent laryngeal nerve injury induced by thyroid gland surgery. METHODS: In this study there were 87 patients with recurrent laryngeal nerve injury, including 65 for nerve exploration and 22 for nonsurgical treatment. During nerve exploration, the types, severity of laryngeal nerve injuries and laryngeal muscular mass were studied. Nerve decompression was performed in these 14 patients whose compressing sutures or compression due to cicatricial hypertrophy were received nerve decompression. RESULTS: Injuries caused by thyroid gland operations mostly are of suture ligation (43%) and nerve severance (48%); simple scar compression was found only in 6 cases (9%). Atrophy of the laryngeal muscles was not very serious in patients with a course less than 6 months. In 10 patients with a course less than three months, nerve decompression restored normal functional abductor and abductor motion of the vocal cord in 9 patients and had no effects in one. Although functional motion of vocal cord was not seen in one case with a course less than 3 months and 4 cases between 3 and 5 months, the mass and tension of the reinnervated vocal cord became much the same as the contralateral normal vocal cord, thus resuming symmetric vibration of the vocal cords and physiological phonation. Although nonsurgical treatment improved severe hoarseness, it didn't restore normal functional motion of the vocal cord and normal voice. CONCLUSIONS: Nerve exploration showed a primary rule for recurrent laryngeal nerve injury induced by thyroid gland surgery. Early and mid-stage recurrent laryngeal nerve exploration and decompression may restore normal motion of the glottis, and it suggested laryngeal delayed reinnervation may help patients with a course more than 6 months.

Adult↗
PubMed2005

[Serious complications of the microvascular decompression in cerebellopontine angle].

OBJECTIVE: To report the serious complications of microvascular decompression and (or) selective neurectomy in cerebellopontine angle. METHODS: To review 322 cases of microvascular decompression and (or) facial nerve splitting, selective neurectomy for hemifacial spasm, trigeminal neuralgia and glossopharyngeal neuralgia respectively. Among 322 cases, hemifacial spasm 164, which 96 underwent facial nerve splitting, 68 underwent microvascular decompression and facial nerve splitting. The selective neurectomy and neurectomy were performed in 128 cases of trigeminal neuralgia and 30 cases for glossopharyngeal neuralgia respectively. RESULTS: Of the serious complications 2 died (0.6%), The mild to severe hearing impairment occurred in 21 cases (6.5%), in which 3 cases presented total hearing loss (0. 9%); Postoperative cerebellospinal leakage in 20 (6. 2%). CONCLUSIONS: It was demonstrated that, even though the microvascular decompression and /or neurectomy was a safe procedure for posterior neuropathy, mortal and serious complications might occur. It was essential to pay great attention to the entire decompression procedure in avoiding cerebellar injury. Using of intraoperative ABR and avoiding of impairment of the acoustic nerve might contribute to the prevention of the postoperative hearing loss.

Adult↗
PubMedDate not supplied

Relationship between two different functions derived from diffusion-based decompression theory.

Hempleman's diffusion-based decompression theory yields two different functions; one is expressed by a simple root function and the other by a complex series function. Although both functions predict the same rate of gas uptake for relatively short exposure times, no clear mathematical explanation has been published that describes the relationship between the two functions. We clarified that (1) the root function is the solution of the one-dimensional diffusion equation for a semi-infinite slab, (2) the series function is an applicable solution for a finite slab thickness, (3) the parameter values of the root function can be used to determine the parameter values of the series function, and (4) the predictions of gas kinetics from both functions agree until an adequate amount of diffusing inert gas reaches the boundary at the opposite end of the finite slab. The last point allows the use of the simpler root function for predicting short no-stop decompression limits. Experience dictates that the inert gas accumulation for a 22 min at 100 feet of seawater (fsw) dive is considered safe for no-stop decompression. Although the constraint, Depth square root of Bottom Time = 100 square root of 22, has been applied as an index to determine either the safe depth or bottom time (given the other) for no-stop decompression, it should not be applied more broadly to dives requiring decompression stops.

Atmospheric Pressure↗
PubMed2006

[Anterior decompression and reconstruction with internal fixation for severe thoracolumbar burst fracture].

OBJECTIVE: To explore the injury mechanism of the severe thoracolumbar burst fracture and the necessity of anterior decompression and reconstruction with internal fixation. METHODS: From January 1999 to January 2004, 21 patients were treated with anterior decompression and reconstruction. The fractures were located at T12 in 6 patients, L1 in 12, L2 in 4, L3 in 3,and L4 in 1. Four patients were treated with the "anterior approach" and "posterior approach" surgeries for severe column fractures. RESULTS: All the patients were restored to the normal physiological radian, and the spinal canal was decompressed completely. They were followed up for 1-6 years, and the bony fusion was observed radiologically. The spinal cord function was improved to the 1-3 Frankel grade in all the patients except 2. There were no such complications as leakage of the cerebrospinal fluid, plate-screw loosening or breaking, or segment instability. The clinical effects were satisfactory. CONCLUSION: The operation of the anterior decompression and reconstruction with internal fixation for severe thoracolumbar burst fracture has advantages of complete decompression, full bone-grafting, and firm internal fixation. It can restore the spinal height and improve the spinal cord function.

Adult↗
PubMedDate not supplied

Optimal interval from decompression to semi-elective operation in sigmoid volvulus.

BACKGROUND/AIMS: The initial non-operative decompression and subsequent semi-elective operation is a common strategy in managing sigmoid volvulus. However, the optimal interval between decompression and operation is still unclear. METHODOLOGY: From 1994 to 2004, 25 patients operated on for sigmoid volvulus at the National Taiwan University Hospital were enrolled. The treatment strategy and clinical outcome in these patients were retrospectively reviewed and analyzed. RESULTS: Twenty-one patients underwent successful non-operative decompression initially, and the remaining 4 patients underwent emergent operation. Gangrene of the colon was found in 3 patients, and all of them eventually died of medical complications, i.e. multiple organ failure, pneumonia and myocardial infarction. One leakage but no mortality occurred in the patients undergoing semi-elective operation. The rate of postoperative complication was not significantly different between the patients operated on 2 days and more than 2 days after the decompression. CONCLUSIONS: The initial non-operative decompression and subsequent semi-elective operation results in a satisfactory outcome in managing sigmoid volvulus. In the view of surgical result, a two-day interval seems adequate for bowel preparation and optimization of the patient's condition.

Adult↗
PubMed2006

Nitrogen load in rats exposed to 8 ATA from 10-35 degrees C does not influence decompression sickness risk.

INTRODUCTION: Environmental temperature is commonly thought to modulate decompression sickness (DCS) risk, but the literature is mixed regarding which conditions elicit the greatest risk. If temperature is a risk factor, then managing thermal exposure may reduce DCS incidence. We analyzed whether hot or cold conditions during or immediately after a hyperbaric exposure altered DCS incidence in a rat model. METHODS: Rats (eight groups of five animals in each of nine conditions; mean body mass +/- SD = 259.0 +/- 9.2 g) were placed in a dry chamber that was pressurized with air to 70 m (8 ATA) for 25 min, followed by rapid (< 30 s) decompression under a series of temperature conditions (35 degrees, 27 degrees, or 10 degrees C during compression; 35 degrees, 20 degrees, or 10 degrees C post-decompression). Animals were observed for 30 min post-decompression for signs of DCS. DCS incidence in the 27 degrees C compression/20 degrees C post-decompression group was 50% by design. Data from all nine groups of paired temperature conditions were compared with each other using analysis of variance, Chi-square tests, and logistic regression. RESULTS: No significant differences in DCS incidence were found among the groups (30-52.5% DCS incidence per group, 42% DCS incidence overall). DISCUSSION AND CONCLUSIONS: This animal model emphasized potential temperature effects attributable to tissue N2 load acquired during compression; there was no evidence that environmental temperature from 10-35 degrees C during or post-dive modulated DCS incidence. It remains to be determined if temperature modulates DCS risk as a function of variable N2 elimination rates.

Animals↗
PubMed1989

The treatment of decompression sickness.

The initial event in decompression sickness is the separation of gas from solution because of supersaturation. If this event gives rise to immediate symptoms, recompression is remarkably effective. This end-point is characteristic of joint pain, that is, Type 1 decompression sickness. Unfortunately the onset of serious Type 2 decompression sickness may be insidious and the delay may be associated with blood-brain barrier dysfunction. Pressure is less effective in the resolution of this problem than a raised partial pressure of oxygen. Standard therapy using oxygen may be associated with worsening of symptoms and air tables with recurrence. Recompression to 4 ata and the use of a mixture of 50% oxygen and 50% helium offers a good working compromise in the treatment of both serious decompression sickness and gas embolism arising in air diving, avoiding the need for a differential diagnosis. Only oxygen or helium and oxygen mixtures should be used in the therapy of decompression sickness in helium and oxygen diving. When therapy has been delayed, intravenous fluids and steroids are important adjuncts.

Atmospheric Pressure↗
PubMed1989

[Emergency treatment in decompression accidents in shipyards].

The Comex company has underwater workplaces scattered over the whole world, which are therefore very often far away from a medical center equipped for the treatment of decompression sickness. However, the subsequent evolution of such an event depends mainly on how fast the first aid is given to the patient. Therefore, the scientific and medical departments of our company developed a medical handbook to be used by chiefs of working platforms. The text which has to be easily understandable, mentions: a cursory description of the clinical signs of the different decompression accidents the measures which have to be taken in each case, depending on: the moment of the emergency: after or during decompression, the presence of an insufficient decompression, or a "blow-up". The handbook contains several recompression tables, first aid treatment recommendations and drugs. It has to be stressed that these procedures are only emergency steps. They should be performed before the patient can be transferred to a medical center with expertise in the treatment of decompression accidents.

Accidents↗
PubMed1988

Treatment of decompression sickness with a perfluorocarbon emulsion (FC-43).

Decompression sickness is caused by the production of tissue and blood stream inert gas bubbles. Perfluorocarbon emulsions (PFC) have enhanced O2 and N2 solubilities as well as a small particle size as properties. The effects of treatment with a PFC (FC-43) and 100% oxygen on decompression sickness were investigated in 24 Sprague-Dawley rats compressed to 6.8 ATA and rapidly decompressed. Survival in animals receiving PFC and 100% oxygen was significantly longer (P = 0.01) than in those receiving a 6% hetastarch (H) treatment. The PFC survivors at 24 h did not demonstrate any neurologic deficits, whereas the 1 H animal surviving at 24 h was ataxic and not eating. Those animals who died most often did so within minutes after decompression, suggesting a hemodynamic demise. We conclude that PFC treatment when coupled with 100% oxygen breathing provides both hemodynamic and neurologic protection from decompression sickness.

Animals↗
PubMedDate not supplied

[Central hemodynamics in man during decompression of the lower extremities].

Experiments were performed to study the effect of leg decompression in the head-down position at -15 degrees. The method of chronic catheterization was used, pressure was measured in different areas of the cardiovascular system, blood was withdrawn for biochemical analysis. The effect of leg decompression was compared with that of lower body negative pressure. Decompression produced changes in PAP and CVP that were similar in sign but different in magnitude. The decompression-induced changes in PAP and CVP were primarily determined by the area of exposure. Using previous data, a monograph was constructed to evaluate PAP and CVP variations as a function of the decompression mode and site.

Adult↗
PubMed1984

[Combined therapy of ventriculo-cisternal irrigation with external decompression in acute ruptured aneurysm].

Vasospasm after clipping of an acute ruptured aneurysm plays an important role in its prognosis. An effective therapy for vasospasm has not been established. We had attempted to remove the subarachnoid clot, which probably caused vasospasm, by ventriculo-cisternal irrigation and had not so good results (A: a group without decompression). Therefore, we have performed a therapy combined ventriculo-cisternal irrigation with external decompression (B: a group with decompression). We wish to report the efficacy of external decompression for an acute ruptured aneurysm. Evaluation of the outcome is due to Table 2. 55% of A group and 80% of B group have a better grade than "fair". Furthermore, a significant difference lies between A and B group associated with symptomatic vasospasm (brain ischemia caused by vasospasm). Namely, A group has all poor or dead cases but B group has 80% of the cases better than "fair". We concluded that relieving ICP by external decompression could suppress the aggravation of the post operative symptomatic vasospasm.

Acute Disease↗
PubMed1984

Application of the compartmentalization/airlock concept to aircraft and tolerance of lung to rapid decompression.

The incidence of pulmonary hemorrhage of different laboratory animals undergoing rapid decompression was found to be markedly decreased by applying the compartmentalization/airlock concept to simulated pressurized aircraft. It was observed that, in protected rabbit, mouse, and rat lungs, 6 of 24 (25%), 7 of 24 (29%), and 6 of 24 (25%), respectively, exhibited a few petechial hemorrhages following rapid decompression. In unprotected animals, however, all 72 lungs showed slight-to-very-severe degrees of decompression-induced hemorrhages. The percent of mortality of the unprotected animals undergoing rapid decompression was 47%, while there were no deaths in protected animals. The incidence of such pulmonary hemorrhages and the mortality of experimental animals indicate that compartmentalization, combined with an adequate airlock, would be of great value in protection against accidental decompression of pressurized aircraft.

Aircraft↗
PubMed1978

Preventive effect of a vasodilator on the occurrence of decompression sickness in rabbits.

The effect of terbutaline on the occurrence of decompression sickness was studied in seven rabbits. Terbutaline is a vasodilator, a sympathomimetic beta2-receptor stimulator. The rabbits were given a hyperbaric exposition at 2 ATA followed by oxygen breathing at 1 ATA and a hypobaric exposition at 0.2 ATA. Each rabbit got a hyperbaric exposition long enough for symptoms of decompression sickness to occur at the hypobaric exposition. With a time interval of at least 1 week, each rabbit received an identical pressure exposition, except that terbutaline was injected intravenously at the beginning of the denitrogenation period at 1 ATA. Of the seven experiments with the drug, only one case of decompression sickness occurred and with a delayed appearance. This may be compared to rapid-appearing decompression sickness in all cases in the control series. The results may be of importance in diving routines and, possibly, in the treatment of decompression sickness.

Animals↗
PubMed1984

The functional and biochemical changes of platelets in experimental decompression sickness of rabbits.

The functional and biochemical changes of rabbit platelets were studied after an exposure to 6 ATA (atmosphere absolute) for 40 min (bottom time). Platelet counts significantly decreased after the decompression. Platelet aggregation induced by collagen was not changed. Although there was no change in the mode volume of platelets after the decompression, the transient appearance of circulating smaller or fragmented platelets suggested a random over-destruction of platelets. Whole and releasable adenine nucleotide contents of platelets were decreased significantly after the decompression. There were no significant changes in cytoplasmic adenine nucleotide contents. Therefore, in decompression sickness, the circulating platelets behaved similarly to those in acquired storage pool disease. Platelet thrombi were found in the pulmonary arteries. These findings suggest that circulating air-bubbles interact with platelets, causing the platelet release reaction, and these activated platelets participate in the formation of thrombi in experimental decompression sickness.

Adenine Nucleotides↗
PubMed1980

Evaluation of different decompression tables by agarose gel method.

Nine different decompression tables were evaluated by the method of bubble formation in the agarose gel, the result of which is summarized as follows: 1) The number of bubbles formed in the agarose gel corresponded well with the exposed pressure. 2) The technique of this method was simple and the number of bubbles was accurately counted. 3) This method was considered useful for examining the decompression tables. 4) Using an equation obtained from the experiment with the same agarose gel, the critical number of bubbles at the end of decompression was found to be 6.6. 5) From this point of view, the R.N.P.L. Table of England and Mano's Model I Table were considered to be excellent. 6) The first stop at the deeper level during the ascent resulted in a smaller number of bubbles at the end of decompression, indicating the effectiveness of this procedure for the prevention of decompression sickness.

Atmospheric Pressure↗