Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Decompression”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources

Incidence of infraorbital hypesthesia and sinusitis after orbital decompression for thyroid-related orbitopathy: a comparison of surgical techniques.

PURPOSE: To compare the incidence of postoperative infraorbital (V2) hypesthesia and sinusitis between transantral/Caldwell-Luc and transconjunctival orbital decompression for thyroid-related orbitopathy. METHODS: A retrospective review of all orbital decompressions from January 1994 to January 2001 performed by one surgeon was done. Seventy-eight patients (133 orbits) with thyroid-related orbitopathy underwent orbital decompression for compressive optic neuropathy, exposure keratopathy, or uncontrolled intraocular pressure. Main outcome measures were the presence of V2 hypesthesia and sinusitis determined at 3 postoperative evaluations (1 to 2 weeks, 1 to 3 months, 3 to 6 months). RESULTS: The incidence of V2 hypesthesia in the transconjunctival group declined from 29.2% (19/65) to 6.1% (4/65), whereas the incidence of V2 hypesthesia in the transantral/Caldwell-Luc group decreased from 68.2% (43/63) to 46% (29/63) over the postoperative course. The rate of sinusitis in the transconjunctival group stayed constant at 6.1% (4/65) at early and late postoperative visits, whereas the transantral group rate of sinusitis declined from 33.3% (21/63) to 9.5% (6/63). CONCLUSIONS: Transconjunctival orbital decompression results in a statistically significant decrease of early and late postoperative infraorbital hypesthesia and early postoperative sinusitis when compared with the transantral approach.

Decompression, Surgical↗

Transcaruncular orbital decompression for management of compressive optic neuropathy in thyroid-related orbitopathy.

This study was conducted to assess the outcome of transcaruncular orbital decompression to treat compressive optic neuropathy in thyroid-related orbitopathy. It involved a retrospective, noncomparative case series of 18 eyes of 10 consecutive patients with documented vision loss secondary to thyroid-related orbitopathy. Bony decompression of the orbital apex was performed via a transcaruncular approach. Main outcome measures were visual acuity, color vision, presence of diplopia, and reduction of exophthalmos. Of 18 eyes, 16 (89 percent) had improved visual acuity after the operation. One eye had no improvement and one had worsening of vision in the setting of diabetic retinopathy. Color vision was improved in 12 eyes (67 percent). Five of the patients did not have diplopia before the operation; none of these patients developed double vision after intervention. Exophthalmos was decreased by an average of 2.6 mm. The authors conclude that transcaruncular orbital decompression for compressive optic neuropathy in thyroid-related orbitopathy is successful in restoring visual function. Compared with other approaches used for decompression surgery, the transcaruncular approach offers direct access to the medial wall and orbital apex without a cutaneous incision or disruption of the medial canthus. In addition, this approach allows a controlled, graded removal of the ethmoidal air cells and reduced recovery time.

Adult↗

Relationship between peripheral nerve decompression and gain of pedal sensibility and balance in patients with peripheral neuropathy.

This was an initial exploratory study to determine if decompression of the 4 medial ankle tunnels (neurolysis of the tibial, medial and lateral plantar, and calcaneal nerves) could lead to improved foot sensibility, increased proprioception and balance, and decreased falls in a population of patients with impaired lower extremity sensation. Fourteen patients with peripheral neuropathy were included in this study. Seventy-one percent of patients were females. Average age was 67 years. All patients were evaluated preoperatively and postoperatively to assess their lower extremity sensibility, as well as their ability to stand still, maintaining their balance with their eyes open and then closed, which is defined as "sway." Lower extremity sensibility was measured with the Pressure-Specified Sensory Device (PSSD), which evaluates 1- and 2-point discrimination for the pulp of the big toe and medial heel. The MatScan Measurement System measured each patient's sway. Neuropathy was the result of diabetes in 72% of patients, a combination of diabetes and hypothyroidism in 7%, chemotherapy in 7%, and idiopathic in 14%. Eight patients underwent peripheral nerve decompression on 1 lower extremity, whereas 6 patients underwent bilateral lower extremity peripheral nerve decompression. Mean toe and heel sensibility improved 9% and 7%, respectively, in the unilateral group, whereas the bilateral group experienced an improvement in mean toe and heel sensibility of 42% (P = 0.02) and 32%, respectively. Preoperative and postoperative sway comparison in the unilateral group revealed a reduction in sway with eyes open and eyes closed by 5% and 31%, respectively. Comparison of preoperative and postoperative sway in the bilateral group showed a reduction with eyes open and eyes closed by 23% and 145% (P = 0.05), respectively. This initial study suggests that there may be benefit from bilateral lower extremity peripheral nerve decompression in helping improve pedal sensibility and balance within the peripheral neuropathy patient population, although further investigation with a larger sample size is warranted to further evaluate these preliminary findings.

Aged↗

Clinical outcome of peripheral nerve decompression in diabetic and nondiabetic peripheral neuropathy.

Surgical decompression of peripheral nerves in patients with diabetes was reported to restore sensation and improve function. In this study, a retrospective review of 12 diabetic and 20 nondiabetic patients with lower-extremity peripheral neuropathy who underwent surgical decompression was performed. Clinical evaluation by Tinel test, muscle power examination, and 2-point discrimination were performed preoperatively, at 6 months, and between 9 and 15 months postdecompression. Clinical outcomes were classified into excellent, good, or fair based on improvement in symptoms and return of function. Thirty-two patients underwent 36 surgeries, in which 99 lower-extremity nerves were decompressed. There was a statistically significant improvement in muscle function (P < 0.001) and 2-point discrimination for the small toe (P = 0.008) and big toe (P = 0.038). At a mean of 7.7 months, 90% of patients showed significant improvement in pain and function. It is concluded that surgical decompression was associated with significant improvement in clinical outcome in patients with diabetic and idiopathic neuropathy with evidence of superimposed compression.

Decompression, Surgical↗

Expression of p53, Ki-67, and EGFR in odontogenic keratocysts before and after decompression.

BACKGROUND: Sixteen odontogenic keratocysts were examined morphologically and immunohistochemically for changes in proliferative activity before and after decompression using p53, Ki-67, and expression of growth factor (EGFR). METHODS: p53 and Ki-67 positivity was scored by counting 500 cells and then counting the number of brown staining nuclei out of these. EGFR was scored using guidelines for scoring Herceptest [Dako (Her-2)]. A Wilcoxon test was performed on the results. RESULTS: The values of Ki-67 and p53 before and after decompression were without significant change. There was no significant change in EGFR expression either. No correlation was found between inflammation or decompression time and expression of EGFR, p53, and Ki-67. The degree of change of the epithelium was varying, yet the reduction of the cysts size was considerable (18-100%- average 47.6%). CONCLUSION: The morphologic changes in the cysts could not be correlated with expression of Ki-67, p53 or EGFR, to the clinical reduction of the cysts or the time of decompression.

Cell Count↗

Results of compartment decompression in chronic forearm compartment syndrome: six case presentations.

BACKGROUND: There are few reports concerning chronic compartment syndrome producing symptoms in the forearm, although in the lower limb this is a well recognised condition. The objective was to demonstrate that chronic compartment syndrome is a cause of exercise induced forearm pain and transient upper limb dysfunction and that forearm compartment decompression can reliably relieve the associated symptoms. METHODS: Six patients with a flexor compartment chronic compartment syndrome, documented by pressure studies, had forearm compartment decompression. RESULTS: All patients had good relief of their exercise associated forearm pain following the decompression. Widening of the incisional scar was frequently reported. CONCLUSION: Forearm compartment decompression is effective in relieving the symptoms related to chronic forearm compartment syndrome.

Adult↗

Self-reported long-term effects of diving and decompression illness in recreational scuba divers.

The aim of this study was to examine the long-term effects of neurological decompression illness (NDCI) on recreational divers. Thirty-seven divers who had been treated for neurological decompression illness at least 2 years previously, and a control group of 50 divers with no history of decompression illness, responded to a postal questionnaire. Divers in the accident group reported more symptoms of neurological damage, were more likely to believe that diving had a deleterious effect on their health and were more likely to indicate symptoms of psychiatric morbidity. The quantity of diving in the year preceding the survey was associated with reports of neurological damage in both groups and with symptoms of psychiatric morbidity in the accident group. Although requiring confirmation from a longitudinal study, these results suggest that recreational diving can have negative long-term consequences for health, particularly after decompression illness.

Adult↗

Neurovascular decompression for idiopathic tarsal tunnel syndrome: technical note.

OBJECTIVE: The surgical outcome of idiopathic tarsal tunnel syndrome (TTS) is reported to be worse than that attributable to ganglion, tarsal coalition, or tumour, and therefore further development in the surgical treatment for idiopathic TTS is considered to be necessary. Here the efficacy of neurovascular decompression for patients with idiopathic TTS is evaluated. METHODS: Twelve feet from nine patients with idiopathic TTS were treated. The patients were aged 52-78 years (mean 64.6 years), and all of them complained of pain or dysaesthesia of the sole of the foot. The posterior tibial nerve was freed from the attached arteriovenous complex (posterior tibial artery and veins). The dissected nerve had a flattened appearance in all of the patients, suggesting nerve compression by the adjacent arteriovenous complex and superficially by the flexor retinaculum. A graft of fat was inserted as both a cushion and an antiadhesive between the vessels and the nerve to achieve neurovascular decompression. RESULTS: Patients on whom neurovascular decompression was performed had resolution or lessening of symptoms in their feet. Neither wound infection nor recurrence of symptoms was found during the follow up period (mean 26.8 months). CONCLUSION: Neurovascular compression syndrome plays a part in idiopathic TTS, and adding neurovascular decompression to resection of the flexor retinaculum is effective.

Aged↗

Predicting time to decompression illness during exercise at altitude, based on formation and growth of bubbles.

For altitude decompressions, we hypothesized that reported onset times of limb decompression illness (DCI) pain symptoms follow a probability distribution related to total bubble volume [V(b.)(t)] as a function of time. Furthermore, we hypothesized that the probability of ever experiencing DCI during a decompression is associated with the cumulative volume of bubbles formed. To test these hypotheses, we first used our previously developed formation-and-growth model (Am J Physiol Regulatory Integrative Comp Physiol 279: R2304-R2316, 2000) to simulate Vb.(t) for 20 decompression profiles in which 334 human subjects performed moderate repetitive skeletal muscle exercise (827 kJ/h) in an altitude chamber. Using survival analysis, we determined that, for a controlled condition of exercise, the fraction of the subject population susceptible to DCI can be approximately expressed as a power function of the formation-and-growth model-predicted cumulative volume of bubbles throughout the altitude exposure. Furthermore, for this fraction, the probability density distribution of DCI onset times is approximately equal to the ratio of the time course of formation-and growth-modeled total bubble volume to the predicted cumulative volume.

Altitude↗

Effect of decompression per se on nitrogen elimination.

The elimination of nitrogen from each of 10 unanesthetized guinea pigs has been monitored after switching to a nitrogen-free breathing mix (normoxic He:O2), either without decompression or on decompression to 2.21 or 1 ATA, following an exposure of 2 h at 4 ATA on normoxic N2;O2. Normoxic conditions were maintained throughout to avoid vasomotor effects of oxygen that could have complicated interpretations derived from previous studies. Results confirmed that inert gas washout rates decrease with decompression per se. This can be explained simply on the basis of the decrease in driving force for nitrogen elimination caused by depositing gas into bubbles where they form in tissue in a somewhat random manner. A very rough estimate shows that about 83% of all body tissue retained its gas in supersaturated solution on decompression to 2.21 ATA but only 79% did so at 1 ATA.

Animals↗

Cross-adaptive effects of cold, hypoxia, or physical training on decompression sickness in mice.

The effects of adaptation to cold, hypoxia, or exercise on hyperbaric decompression tolerance were investigated in two factorial experiments. For either 14 or 28 days, groups of mice were handled (control); exposed discontinuously for 4 h to cold (4 degrees C) or hypoxia (P approximately 379 or 320 Torr); or exercised by swimming (15 min at 31 degrees C) or treadmill excursion (8.1 m/min for 1 or 1.5 h). The animals were divided into subgroups, exposed to one of three hydrostatic pressures (7.6--11.1 ATA) for 30 min, decompressed, and observed to determine survival rate or bends incidence (type II decompression sickness). Decompression sickness was significantly reduced (P less than 0.05) in the treadmill-trained animals, was unchanged in cold-exposed and swim-exercised mice, and tended to increase in animals adapted to hypoxia. Enhanced tolerance by treadmill training is presumably due to lean body conformation, which could reduce nitrogen saturation of tissues, and greater muscle capillarization and cardiovascular fitness, which may improve nitrogen elimination. Reduced tolerance with adaptation to hypoxia may be attributed to rheological changes associated with polycythemia, which facilitate bubble production.

Adaptation, Physiological↗

Human dose-response relationship for decompression and endogenous bubble formation.

The dose-response relationship for decompression magnitude and venous gas emboli (VGE) formation in humans was examined. Pressure exposures of 138, 150, and 164 kPa (12, 16, and 20.5 ft of seawater gauge pressure) were conducted in an underwater habitat for 48 h. The 111 human male volunteer subjects then ascended directly to the surface in less than 5 min and were monitored for VGE with a continuous-wave Doppler ultrasound device over the precordium or the subclavian veins at regular intervals for a 24-h period. No signs or symptoms consistent with decompression sickness occurred. However, a large incidence of VGE detection was noted. These data were combined with those from our previously reported experiments at higher pressures, and the data were fit to a Hill dose-response equation with nonlinear least-squares or maximum likelihood routines. Highly significant fits of precordial VGE incidences were obtained with the Hill equation (saturation depth pressure at which there is a 50% probability of detectable VGE [D(VGE)50] = 150 +/- 1.2 kPa). Subclavian monitoring increased the sensitivity of VGE detection and resulted in a leftward shift [D(VGE)50 = 135 +/- 2 kPa] of the best-fit curve. We conclude that the reduction in pressure necessary to produce bubbles in humans is much less than was previously thought; 50% of humans can be expected to generate endogenous bubbles after decompression from a steady-state pressure exposure of only 135 kPa (11 ft of seawater). This may have significant implications for decompression schedule formulation and for altitude exposures that are currently considered benign. These results also imply that endogenous bubbles arise from preexisting gas collections.

Adult↗

Predicting the time of occurrence of decompression sickness.

Probabilistic models and maximum likelihood estimation have been used to predict the occurrence of decompression sickness (DCS). We indicate a means of extending the maximum likelihood parameter estimation procedure to make use of knowledge of the time at which DCS occurs. Two models were compared in fitting a data set of nearly 1,000 exposures, in which greater than 50 cases of DCS have known times of symptom onset. The additional information provided by the time at which DCS occurred gave us better estimates of model parameters. It was also possible to discriminate between good models, which predict both the occurrence of DCS and the time at which symptoms occur, and poorer models, which may predict only the overall occurrence. The refined models may be useful in new applications for customizing decompression strategies during complex dives involving various times at several different depths. Conditional probabilities of DCS for such dives may be reckoned as the dive is taking place and the decompression strategy adjusted to circumstance. Some of the mechanistic implications and the assumptions needed for safe application of decompression strategies on the basis of conditional probabilities are discussed.

Decompression Sickness↗

Predicting risk of decompression sickness in humans from outcomes in sheep.

In animals, the response to decompression scales as a power of species body mass. Consequently, decompression sickness (DCS) risk in humans should be well predicted from an animal model with a body mass comparable to humans. No-stop decompression outcomes in compressed air and nitrogen-oxygen dives with sheep (n = 394 dives, 14.5% DCS) and humans (n = 463 dives, 4.5% DCS) were used with linear-exponential, probabilistic modeling to test this hypothesis. Scaling the response parameters of this model between species (without accounting for body mass), while estimating tissue-compartment kinetic parameters from combined human and sheep data, predicts combined risk better, based on log likelihood, than do separate sheep and human models, a combined model without scaling, and a kinetic-scaled model. These findings provide a practical tool for estimating DCS risk in humans from outcomes in sheep, especially in decompression profiles too risky to test with humans. This model supports the hypothesis that species of similar body mass have similar DCS risk.

Algorithms↗

Posterior fossa decompression without duraplasty in infants and young children for treatment of Chiari malformation and achondroplasia.

Some children with Chiari malformation and achondroplasia require posterior fossa decompression that typically includes expansion of the dural tube with duraplasty. Infants and young children, however, may have a more distensible dura mater than do older patients. Furthermore, the structures that compress the hindbrain of young patients may be the bone and abnormally thickened atlantooccipital membrane, i.e., dural band, rather than the dura mater. We have treated 7 children who had Chiari malformation or achondroplasia with posterior fossa decompression without duraplasty. All children were symptomatic; 3 had Chiari-I malformations, 2 Chiari-II malformations, and 2 achondroplasia. The age range was 3 months to 2.5 years (mean 15.1 months). The exent of tonsillar herniation and other hindbrain anomalies was assessed on preoperative magnetic resonance imaging. The infants with Chiari-II malformations underwent cervical laminectomies, whereas the other young children with Chiari-I malformations or achondroplasia underwent suboccipital craniectomy as well as cervical laminectomy. In Chiari malformation, the dural band was divided; in achondroplasia, there was no identifiable dural band. Following bony decompression and division of the identifiable dural band, immediate expansion of the stenotic region with visible cerebrospinal fluid space posterior to the neural elements could be ascertained by intraoperative ultrasonography. During a follow-up period ranging from 4.5 months to 4 years (mean 22 months), all patients made improvements in their symptoms, 3 having complete resolution of their symptoms. This preliminary experience indicates that in children 2 years of age or younger, posterior fossa bony decompression without duraplasty can be effective treatment for Chiari malformations or achondroplasia.

Achondroplasia↗

Long-term results after microvascular decompression in essential hypertension.

BACKGROUND AND PURPOSE: In 1998, 8 patients with severe, intractable arterial hypertension and MR tomography-demonstrated neurovascular contact of a looping artery at the root entry zone of cranial nerves IX and X, causing neurovascular compression, underwent neurosurgical decompression. The short-term results showed a normalization of blood pressure with a markedly reduced antihypertensive drug regimen in 7 patients. To determine the longer-term outcome concerning blood pressure and secondary organ damage after neurovascular decompression, we studied these 8 operated patients prospectively for a mean follow-up of 3.5 years after surgical intervention. METHODS: Eight hypertensive patients who had undergone microsurgical decompression were monitored every 6 months after surgery to assess blood pressure (by 24-hour ambulatory pressure readings) and the need for antihypertensive medication. To evaluate secondary organ damage, echocardiographic assessment of left ventricular hypertrophy, fundoscopic assessment of hypertensive lesions, and analysis of renal function and proteinuria were done. RESULTS: Three of the 8 operated patients remained normotensive in the long-term period with decreased antihypertensive medication. Two patients required gradual increases of antihypertensive medication after the first postoperative year, after which arterial blood pressure levels were 10% to 15% lower than preoperative levels. Three patients suffered serious cardiovascular and renal complications, with the incidence of lethal intracerebral hemorrhage in 1 patient and end-stage renal disease in 2 patients, of whom 1 experienced sudden cardiac death. CONCLUSIONS: The long-term results verify that microsurgical decompression is a successful alternative therapy in a certain subgroup of patients with arterial hypertension due to neurovascular compression. However, the relevance of the looping artery in the other cases, who did not improve, is not clear. Prospective studies to elucidate the pathophysiological role of neurovascular abnormalities and arterial hypertension are needed.

Adult↗

Higher Rates of PASS and SCB After Arthroscopic Subspine Decompression Are Associated With a Positive Diagnostic AIIS Injection: A Propensity Score-Matched Cohort Study.

BACKGROUND: Hip arthroscopy effectively treats femoroacetabular impingement syndrome (FAIS), but persistent pain may be related to concomitant extra-articular pathology such as subspine impingement syndrome (SSI). Standard diagnosis of SSI often relies on 3-dimensional computed tomography (3D-CT) morphology (Hetsroni type II/III), although this morphology is common in individuals who are asymptomatic and correlates poorly with symptoms. PURPOSE: To compare minimum 2-year clinical outcomes after arthroscopic subspine decompression in patients with concurrent FAIS and type II/III anterior inferior iliac spine (AIIS) morphology, stratified by diagnostic method: 3D-CT morphology alone versus 3D-CT morphology plus a positive ultrasound-guided diagnostic injection. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This study included patients aged 18 to 55 years with type II/III AIIS morphology who underwent primary hip arthroscopy for FAIS and SSI between January 2021 and November 2023 and had minimum 2-year follow-up. Patients diagnosed by CT morphology alone (CT classification group) were propensity score matched 1:1 to patients with a positive ultrasound-guided AIIS injection (injection group), with 57 patients per group. Matching variables were age, sex, body mass index, lateral center-edge angle, alpha angle, T&#xf6;nnis grade, and Beighton score. All patients underwent arthroscopic subspine decompression. Patient-reported outcomes and rates of achieving the minimal clinically important difference, Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB) were compared. RESULTS: Preoperative patient-reported outcome scores were similar between groups (all P > .05). At minimum 2-year follow-up, the injection group had significantly better scores on the modified Harris Hip Score (90.8 vs 84.2), Hip Outcome Score-Activities of Daily Living (88.4 vs 82.4), Hip Outcome Score-Sports Subscale (71.9 vs 64.1), 12-item International Hip Outcome Tool (83.9 vs 76.1), and visual analog scale for pain (1.2 vs 2.0) (all P < .001). Minimal clinically important difference rates were high in both groups, with higher rates in the injection group for modified Harris Hip Score (93% vs 77%; P = .033) and Hip Outcome Score-Activities of Daily Living (91% vs 75%; P = .042). PASS and SCB rates were significantly higher in the injection group across all patient-reported outcome measures (all P < .05). Revision and complication rates were low and did not differ significantly between groups. CONCLUSION: Both groups improved significantly after arthroscopic subspine decompression. However, patients with a positive ultrasound-guided diagnostic AIIS injection achieved higher PASS and SCB rates than those selected by CT morphology alone, suggesting that injection-confirmed SSI may improve patient selection for subspine decompression.

Humans↗

Comparative study of vitrectomy with and without vein decompression for branch retinal vein occlusion: a pilot study.

PURPOSE: To report the clinical outcomes in patients undergoing pars plana vitrectomy with and without vein decompression for treatment of branch retinal vein occlusion (BRVO). METHODS: Thirty-five eyes with macular edema and visual acuity worse than 20/100 secondary to BRVO were prospectively evaluated. Vitrectomy with posterior hyaloid removal and vein decompression at the arteriovenous crossing was performed on 15 eyes (Group 1); consecutively, the same technique without vein decompression was performed on 20 eyes (Group 2). Primary outcome was visual acuity and secondary outcomes were resolution of macular edema and development of neovascularization. RESULTS: No differences were found between groups in either patient age (p = 0.566) or preoperative visual acuity (p = 0.505). No differences were found in visual acuity at 3 (p = 0.651), 6 (p = 0.697), 9 (p = 0.763), 12 (p = 0.881), or 18 (p = 0.748) months. Mean time for macular edema resolution and visual acuity improvement was 9 months in both groups, with a mean improvement of 3.5 +/- 2.35 lines in Group 1 and 3.2 +/- 2.97 lines in Group 2. No eyes in either group developed new vessels. CONCLUSIONS: Results suggest that vitrectomy with posterior hyaloid removal without vein decompression can resolve macular edema, improve vision, and prevent development of new vessels in BRVO.

Aged↗