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Elective lumbar spinal decompression in the elderly: is it a high-risk operation?

INTRODUCTION: Spinal degeneration leading to spinal stenosis is increasingly common in an aging population. Many patients are not referred for operation because of the fear of severe complications. The purpose of this study was to relate the surgical risks involved in elective spinal decompression in elderly patients to those of total hip arthroplasty, a well-accepted procedure whose risks and benefits are well known. METHODS: We reviewed the charts of 6 8 consecutive patients who underwent elective spinal decompression and fitted our inclusion criteria (65-80 yr of age, no spinal or hip operations, no hip fractures, spine fractures or cauda equina syndrome and no bone or metastatic disease). This group was matched with a similar group of 68 randomly selected patients who underwent total hip arthroplasty during the same period. We recorded the age, gender, American Society of Anesthesiologists (ASA) score, early postoperative complication rate, operative time, hospital stay and blood lost. RESULTS: The 2 groups were well matched with respect to age, gender and ASA score. The only significant intraoperative difference was operative time, with the spine procedure taking longer to complete (191 min v. 278 min). Blood loss was not significantly different. Both groups had a similar number of lift-threatening complications (12 v. 14). The number of minor complications was greater in the spinal decompression group (62 v. 125). CONCLUSIONS: Elective lumbar spinal decompression in elderly patients suffering significant pain or disability due to degenerative lumbar spinal stenosis is worthwhile. We recommend judicious use of conservative measures, but encourage referral for surgical management when these fail. This operation, even when instrumentation and bone grafting are required, is not associated with more serious or life-threatening risks than a total hip replacement in elderly patients.

Aged↗

Multiple sclerosis presenting as neurological decompression sickness in a U.S. navy diver.

A case of clinically definite multiple sclerosis presenting as neurological decompression sickness is presented. A 23-yr-old U.S. Navy diver experienced onset of hypesthesia of the left upper trunk approximately 19 h after making two SCUBA dives. She did not seek medical attention until 3 wk later, at which time she was diagnosed with possible neurological decompression sickness. She was treated with hyperbaric oxygen, but demonstrated no improvement. Further evaluation led to the diagnosis of multiple sclerosis. This case underscores the potential similarity in neurological presentation between multiple sclerosis and decompression sickness. The differential diagnosis of neurological decompression sickness, particularly in atypical cases, should include multiple sclerosis. The appropriateness of medically clearing multiple sclerosis patients for diving is discussed.

Adult↗

[Endoscopic optic nerve decompression in traumatic visual loss].

OBJECTIVE: To review our experience of treatment of optic nerve decompression in traumatic visual loss by using endoscopic technique. METHOD: Fourteen cases patients with traumatic visual loss were undergone endoscopic optic nerve decompression. All patients were followed up for 3-18 months. RESULT: Eight cases had improved visual acuity, and 6 cases did not. No complication had happened. CONCLUSION: Endoscopic optic nerve decompression is an appropriate technique for patients with traumatic visual loss. Even though high-dose steroid treatment has failed, optic nerve decompression may improve visual acuity.

Adolescent↗

[Surgical arteriovenous decompression (sheathotomy) in branch retinal vein occlusion: retrospective study].

PURPOSE: To evaluate best-corrected visual acuity (BCVA), incidence of neovascularization and angiographic changes in patients with branch retinal vein occlusion (BRVO) treated with surgical decompression by sheathotomy. METHODS: Retrospective study including 17 cases of temporal BRVO with macular edema treated with surgical decompression. Results of BCVA, incidence of neovascularization and vitreous hemorrhage 6 months following surgery are included. Angiographic changes in the first 8 cases a month after decompression are also evaluated. RESULTS: The mean postoperatory BCVA was 0.40 with a mean improvement of 0.26. Seventy one percent of patients (12/17) improved 2 or more visual acuity lines and 53% of patients (9/17) improved 4 or more lines. Only in one case the vision worsened. There was no evidence of retinal neovascularization or rubeosis iridis six months after surgery. CONCLUSIONS: Surgical decompression is a therapeutical option for those patients suffering BRVO with macular edema. Our initial results are encouraging, not only regarding visual acuity improvement, but also because of a decreased risk of neovascularization. No patient included in our study developed neovascularization.

Decompression, Surgical↗

Effect of craniocervical decompression on peak CSF velocities in symptomatic patients with Chiari I malformation.

BACKGROUND AND PURPOSE: Peak CSF velocities detected in individual voxels in the subarachnoid space in patients with Chiari I malformations exceed those in similar locations in the subarachnoid space in healthy subjects. The purpose of this study was to test the hypothesis that the peak voxel velocities are decreased by craniocervical decompression. METHODS: A consecutive series of patients with symptomatic Chiari I malformations was studied before and after craniocervical decompression with cardiac-gated, phase contrast MR imaging. Velocities were calculated for each voxel within the foramen magnum at 14 time points throughout the cardiac cycle. The greatest velocities measured in a voxel during the cephalad and caudad phases of CSF flow through the foramen magnum were tabulated for each patient before and after surgery. The differences in these velocities between the preoperative and postoperative studies were tested for statistical significance by using a single-tailed Student's t test of paired samples. RESULTS: Eight patients with a Chiari I malformation, including four with a syrinx, were studied. Peak caudad velocity diminished after craniocervical decompression in six of the eight patients, and the average diminished significantly from 3.4 cm/s preoperatively to 2.4 cm/s postoperatively (P =.01). Peak cephalad velocity diminished in six of the eight cases. The average diminished from 6.9 cm/s preoperatively to 3.9 cm/s postoperatively, a change that nearly reached the significance level of.05 (P =.055). CONCLUSION: Craniocervical decompression in patients with Chiari I malformations decreases peak CSF velocities in the foramen magnum. The study supports the hypothesis that successful treatment of the Chiari I malformation is associated with improvement in CSF flow patterns.

Arachnoid↗

[Transcranial optic nerve decompression for optic nerve injury].

OBJECTIVE: To discuss the operative indications and advantages of transcranial optic nerve decompression in treatment of optic nerve injury resulted from skull base fracture. METHODS: The data, such as the site of impact, vision, ocular movement, characteristic of CT, and pathologic changes during operation, and the extent of operative decompression of 118 patients with optic nerve injury. According the site of impact on the head, 87 of lateral superciliary arch type, 18 of medial superciliary arch type, and 13 of zygomatic type, undergoing transcranial optic nerve decompression were analyzed retrospectively. The patients were followed up for 6 months after operation. For the purpose of evaluation, the postoperative outcome of visual acuity was classified into five grades: blindness, hand movement, finger count, light perception and visual acuity > 0.05. The visual acuity improvement reaching one grade or more was defined as effective. The improvement of visual field was also considered effective. RESULTS: After follow-up of 6 months, effect was shown in 35 out of the 72 patients with pre-operative blindness (48.6%), and all the 46 patients with residual vision (100%). The total effective rate was 68.6%. The post-operative effective rate was 64.4% in patients with lateral superciliary arch type, 83.3% in patients with medial superciliary arch type injury and 76.9% in patients with zygomatic type injury. CONCLUSIONS: Transcranial optic nerve decompression is worthy recommending to the patients with traumatic optic neuropathy. The operative indications include patients with residual vision; patients with bilateral optic nerve injury; and patients with blindness less than 3 days.

Adolescent↗

Decompressive shunts and hepatic encephalopathy.

Encephalopathy is a major complication of all decompressive procedures done to reduce portal pressure. There are two major groups of decompressive procedures: surgical portosystemic shunts and transjugular intrahepatic portosystemic shunts (TIPS). Surgical decompressive shunts are of three types: total, partial and selective, depending on the amount of hepatopetal flow that is maintained in each of them. Encephalopathy with these shunts occurs because of reduction in hepatopetal flow. These shunts have failed to reduce mortality; in fact, some studies have shown an increase in mortality following shunts. TIPS has more or less replaced the need for surgical shunts, but their risk to cause encephalopathy is almost equivalent to that of selective shunts and in some series is even more. Lactulose, antibiotics and protein restriction can easily control severe encephalopathy as a consequence of decompressive shunts.

Decompression, Surgical↗

Endonasal endoscopic orbital decompression in patients with Graves' ophthalmopathy.

AIM: To present the results of endonasal endoscopic orbital decompression in patients with Graves' ophthalmopathy. METHODS: Endonasal endoscopic orbital decompression was performed in 32 orbits of 21 patients with Graves' ophthalmopathy. In 17 patients the surgery was performed because of active ophthalmopathy non-responsive to conservative treatment, and in 4 patients for esthetic reasons. Preoperative and postoperative examination included visual acuity, examination of the eyelids and cornea, ocular motility, cover testing, Hertel exophthalmometry, and applanation tonometry. RESULTS: Visual acuity improved from preoperative 0.81+/-0.28 (mean +/- standard deviation) to postoperative 0.92+/-0.21 (p=0.0032, Student t-test). Retraction of upper and lower eyelids, as well as exposure keratitis, was reduced after operation (p<0.001). Mean proptosis reduction in all orbits was 4.6+/-1.7 mm (p<0.001). An average reduction of intraocular pressure was 3.4+/-3.0 mmHg (p<0.001). New-onset diplopia developed in 8 patients. Diplopia persisted in 9 out of 11 patients who had preoperative diplopia. Two patients experienced postoperative relief of diplopia. Ocular motility was subsequently corrected by eye muscle surgery in 13 eyes, whereas prisms were used in other 5 manifestly strabic eyes. CONCLUSIONS: Endonasal endoscopic orbital decompression procedure improved visual acuity, decreased proptosis and intraocular pressure, and also had favorable cosmetic results in most patients. Post decompression diplopia and strabismus were successfully managed by either eye muscle surgery or application of prisms.

Adult↗

Probabilistic model of decompression sickness based on stochastic models of bubbling in tissues.

BACKGROUND: Decompression sickness (DCS) is caused by gas bubbles formed from pre-existing and new microscopic gas nuclei in blood and tissues. Assuming a random pattern of bubbling processes in living tissues, we developed a probabilistic model of DCS. We hypothesized that symptoms of DCS in an individual exposed to decompression appear when the total volume of bubbles in a unit volume of any tissue, w(t), exceeds the critical specific volume of a free gas phase, wcr. Therefore, one may consider the expectation of w(t)/wcr as a measure of the dynamic risk of gas bubble lesion of a given tissue segment. METHODS: Using the standard approach to estimation of various risks and the sum rule of probabilities of joint events, we defined the cumulative probability of DCS onset by the equation Pcum(t) = 1 - exp[Fcum(t)], where Fcum(t) = sigmaVnQnMnc(t), Qn = 1/wncr, where Vn is the volume of a tissue n. The function Mnc(t) coincides with the function Mn(t), defining a time history of the expectation of wn(t) until it achieves its maximum and then becomes a constant. Evaluating Pcum(t) for particular altitude decompressions, we identified the additive cumulative risk function of development of any DCS symptoms, Fcum-tot(t), with the function defining the cumulative risk of any bubble lesion of the "worst" virtual tissue (WVT) of Type A. On the other hand, we identified the additive cumulative risk function of development of intolerable DCS symptoms, Fcum-int(t), with the function defining the cumulative risk of acute bubble lesion of the WVT of Type phi. RESULTS: We found parameters of the curves Pcum-tot(t) and Pcum-int(t) that fit the known empirical curves for the cumulative probability of DCS onset. For men performing mild exercise at 30 kPa after preoxygenation, our estimated parameters for curves Pcum-tot(t) indicate that the WVTs of Type A have nitrogen washout half-times of 260 and 290 min for preoxygenation times of 75 and 135 min, respectively. On the other hand, the parameters of curves Pcum-int(t) show that the WVTs of Type phi in men performing mild exercise at 20-40 kPa after preoxygenation during 0-6 h are virtual tissues with nitrogen washout half-times of 400 to 615 min. CONCLUSION: Our model provides a new approach to predicting DCS risk for various decompression profiles. By demonstrating the dependence of DCS risk on body tissue parameters, the model explains why resistance to DCS in mammals increases with a lower body mass and greater specific blood flow in tissues.

Decompression Sickness↗

[Otoendoscopic tympanic segment and ganglion geniculi of facial nerve decompression via the attic approach].

OBJECTIVE: To research the practicability of otoendoscopic tympanic segment and ganglion geniculi of facial nerve decompression via the attic approach and the advantage of the operative procedure. METHOD: 12 patients with traumatic peripheral facial paralysis following temporal bone fracture (n = 11) and radical mastoidectomy (n = 1) underwent otoendoscopic tympanic segment, pyramidal segment or ganglion geniculi of facial nerve decompression via the attic approach. The injured positions were estimated before operation by high resolution CT scan, Schirmer test, acoustic reflex, taste test and hearing examination. RESULT: The facial muscle function of 6 cases (50%) recovered totally at time of discharge by Hosuse-Brackmann Standard. After 2-10 months of following up, 4 cases (33.3%) recovered totally and 2 cases (16.7%) remained light to medium facial paralysis. After operation, the hearing level unchanged (n = 8), descended (n = 2) and improved (n = 2) with auditory ossicle dislocation before operation. CONCLUSION: Otoendoscopic assisted tympanic segment and ganglion geniculi of facial nerve decompression via the attic approach can reach the target convenient and minimally destroyed normal structure. It is a mini-invasive approach for facial nerve decompression.

Adolescent↗

Multidisciplinary approach to abdominal wall reconstruction after decompressive laparotomy for abdominal compartment syndrome.

INTRODUCTION: Decompressive laparotomy for abdominal compartment syndrome has been shown to reduce mortality in critically ill patients, but little is known about the outcome of abdominal wall reconstruction. This study investigates the role of plastic surgeons in the management and reconstruction of these abdominal wall defects. METHODS: We performed a retrospective review of 82 consecutive critically ill patients who underwent decompressive laparotomy for abdominal compartment syndrome, at a university level 1 trauma center, from April 2000 to May 2004. Patients reconstructed by trauma surgeons alone (n = 15) were compared with patients reconstructed jointly with plastic surgeons (n = 12), using Student t test and chi analysis. RESULTS: Eighty-two patients underwent decompressive laparotomy for abdominal compartment syndrome, yielding 50 survivors (61%). Of the 27 patients who underwent abdominal wall reconstruction, 6 had early primary fascial repair, and 21 had staged reconstruction with primary fascial closure (n = 4), components separation alone (n = 3), components separation with mesh (n = 10), or permanent mesh only (n = 4). Compared with patients whose reconstruction was performed by trauma surgeons, patients who underwent a combined approach with plastic surgeons were older (50.5 versus 31.7 years, P < 0.05), had more comorbidities (P < 0.001), were less likely to have a traumatic etiology (P < 0.001), had a longer delay to reconstruction (407 versus 119 days, P < 0.05), and were more likely to undergo components separation (P < 0.05). Mean follow-up of 11.5 months revealed 2 recurrent hernias in the combined reconstruction group, both of which were successfully repaired. CONCLUSIONS: A multidisciplinary approach is essential to the successful management of abdominal wall defects after decompressive laparotomy for abdominal compartment syndrome. Although carefully selected patients can undergo early primary fascial repair, most of reconstructed patients had staged closure of the abdominal wall via components separation, with a low rate of recurrent hernia. High-risk patients with large defects and comorbidities appear to benefit from the involvement of a plastic surgeon.

Abdomen↗

Isoproterenol accelerates decompression sickness and death after saturation dives in swine.

BACKGROUND: Disabled submarine (DISSUB) survivors are expected to achieve inert gas tissue saturation that would likely cause severe decompression sickness (DCS). Rescue procedures in a DISSUB scenario cannot accommodate a staged decompression and the availability of recompression treatment chambers is limited. Alternatives to the standard recompression procedures for treating DCS are needed. Experimentally, isoproterenol has successfully addressed many underlying physiological concerns expected to result in cardiopulmonary DCS in this group. HYPOTHESIS: We hypothesized that isoproterenol would reduce the incidence of cardiopulmonary DCS in a saturation dropout model. METHODS: Yorkshire swine (21.8 +/- 1.68 kg) were fitted with an external jugular catheter and compressed to 4.33 ATA in a dry chamber for 22 h. They were infused with isoproterenol (0.002 mg x kg(-1)) while still at depth and returned to the surface without decompression stops. They received additional infusions every 10 min throughout a 2-h observation period. Signs of DCS were recorded to the nearest minute. RESULTS: Isoproterenol administration resulted in a significant increase in the incidence of severe cardiopulmonary DCS (13/34 control vs. 12/18 isoproterenol) and death from DCS (10/34 control vs. 11/18 isoproterenol). There was no difference in the incidence of severe neurological DCS. CONCLUSIONS: Administering isoproterenol as an intervention/treatment for DCS significantly increases the risk of cardiopulmonary DCS and death following saturation dropout in 20-kg swine. As an adjunctive therapy or alternative to staged decompression, isoproterenol in the dose regimen delivered here is not expected to improve outcome in a DISSUB mass casualty scenario.

Adrenergic beta-Agonists↗

[A study on etiology and pathogenic mechanism of decompression sickness].

OBJECTIVE: To explain the etiology of decompression sickness (DCS) and to elucidate its pathogenic mechanism. METHOD: Tunica conjunctiva was examined by microscopy and blood pressure was measured at the exposed femoral arteries in inadequately decompressed animals after hyperbaric exposure. Then pathological examinations were done. RESULT: Animals with vascular spasm and dysfunction after decompression showed DCS symptoms. Severe DCS was found in the period of increasing of blood pressure swelling. Appeared in endothelial cells, fracted, hemorrhages were also formed in the body of DCS animals. CONCLUSION: DCS is a disease with vascular spasm and dysfunction caused by decompression. It's resulted from anoxia or pathological change caused by vascular spasm, dysfunction or even failure of blood vessels due to the gas tension (etiology) provoked by supersaturated gas in the blood during descending of ambient pressure. Vascular spasm and dysfunction impede the elimination of gas from the blood, and once the gas amount is sufficient to cause severe ischemia of the circulation system, the state of disease would be severe.

Animals↗

[Therapeutic effects of anterolateral decompression and fixation on thoracolumbar fractures complicated with incomplete paraplegia].

OBJECTIVE: To investigate the clinical effects of anterolateral decompression and fixation on thoracolumbar fractures complicated with incomplete paraplegia. METHODS: Thirty-six patients with thoracolumbar fractures complicated with incomplete paraplegia were treated with anterolateral decompression and fixation. RESULTS: The patients were followed up for an average of 18 months, which showed satisfactory recovery of the intervertebral space height and thoracolumbar vertebral curvature. The average Cobb's angle, spinal canal index and Frankel were improved remarkably, and none of the patients developed such complications as break or mobilization of the plate screw. CONCLUSION: Anterolateral decompression and fixation can directly and completely decompress the vertebral canal, promote the functional recovery of the spinal nerves and reconstruct the alignment of the spine as an ideal approach for treatment of thoracolumbar fractures with obvious spinal canal-occupying lesions or severe kyphos complicated with incomplete paraplegia.

Adolescent↗

Treatment of osteonecrosis of the femoral head by percutaneous decompression and autologous bone marrow mononuclear cell infusion.

OBJECTIVE: To evaluate the clinical efficacy and safety of the treatment of osteonecrosis of the femoral head by percutaneous decompression and autologous bone marrow mononuclear cell (BMCs) infusion. METHODS: 44 hips in 28 patients with avascular necrosis at early stage were treated by percutaneous multiple holes decompression followed by autologous BMCs infusion. Autologous BMCs were concentrated from bone marrow that was taken from the posterior iliac crest of the patient. Patients were followed up at least 2 years. The results were determined by the changes in the Harris hip score and the progression in the radiograghic stages. RESULTS: No complications were observed after the operation. Before operation, there were stage I of femoral head necrosis in 8 hips, stage II in 15 hips, stage III in 14 hips, stage IV in 7 hips, and the postoperative stages at the most recent follow-up were stage O in 1 hip, stage I in 6 hips, stage II in 13 hips, stage III in 13 hips, stage IV in 7 hips, stage V in 4 hips. The mean preoperative Harris hip score was 58 (46-89), and improved to 86 (70-94) postoperatively. All the femoral head collapsed preoperatively showed that the necrotic size was at least more than 30%. CONCLUSIONS: Percutaneous multiple holes decompression combined with autologous BMCs is a new way to treat avascular necrosis of the femoral head. The earlier the stage, the better the result. A randomized prospective study needed to compare with routine core decompression in the future.

Adolescent↗

[Endoscopic optic nerve decompression in traumatic optic neuropathy: analysis of 72 cases].

OBJECTIVE: To review the effects of optic nerve decompression by endoscopic technique in traumatic optic neuropathy. METHODS: Seventy-two patients (73 eyes) with traumatic optic neuropathy which were treated with large dose of glucocorticoid but inefficacious were undergone endoscopic optic nerve decompression. The days from injury to surgery were 1-57 d. Among that, < or = 3 d 15 cases, 4-7 d 37 cases, 8-10 d 9 cases, 11-15 d 5 cases, 16-30 d 5 cases, >30 d 1 cases. The vision of pro-operation: with light perception or higher grades 18 eyes; with no light perception 55 eyes. RESULTS: All patients were followed up for more than 3 months. Fourty-six of 73 eyes had improvements in visual acuity, the total effective rate was 63.01%. Thirty-one of 55 eyes with no light perception had raises in visual acuity (56.36%). Fifteen of 18 eyes with light perception or higher grades had improvements (83.33%). No complication had happened. CONCLUSIONS: Endoscopic optic nerve decompression is an appropriate technique for patients with traumatic optic neuropathy. Even though the patient has injured in longer time and high-dose steroid treatment has failed, optic nerve decompression may improve visual acuity.

Adolescent↗

[Abnormal muscle response monitoring during microvascular decompression for hemifacial spasm and long term results].

OBJECTIVE: There is some debate over the reliability of intraoperative abnormal muscle response (AMR) monitoring as an indicator of postoperative long-term outcome in patients with hemifacial spasm (HFS). We investigated whether AMR findings obtained during microvascular decompression reflect postoperative long-term outcome. MATERIAS AND METHODS: Subjects were 51 HFS patients who underwent AMR monitoring during surgery. AMR recordings were obtained from the mentalis muscle by electrical stimulation of the temporal branch of the facial nerve and from the orbicularis oculi muscles by stimulation of the marginal mandibular branch. Postoperative follow-up was more than 5 years (range 61-118 months, mean 87 months). RESULTS: In 37 patients, AMR disappeared after vascular decompression. Among those patients, only one presented with spasm at the final follow-up examination. In 6 of 7 patients with AMR that disappeared early before the completion of decompression, hemifacial spasm resolved completely. Five of six patients in whom AMR still remained but with decreased amplitude at the end of surgery experienced complete resolution. CONCLUSIONS: Our findings suggest that intraoperative cessation including prior to decompression or decreased amplitude of AMR at the end of surgery indicates a high likelihood of postoperative long-term relief of HFS. We believe that intraoperative AMR monitoring is useful in MVD surgery for HFS.

Adult↗

Decompression sickness: USN operational experience 1969-1989.

This report presents data on the U.S. Navy's experience in decompression sickness occurring in operational flight from 1 January 1969 to 30 December 1989. During these 21 years, decompression sickness was reported in 12 USN aircraft and involved 15 aircrew. The primary cause of decompression, as might be expected, was a loss of cabin or cockpit pressurization. The most common manifestation of decompression sickness was limb or joint pain although some crewmembers experienced various manifestations of neurological dysfunction. One crewmember experienced chokes. Of the 15 afflicted aircrew, 13 (87%) had complete remission of symptoms by the time they landed. Two crewmembers required compression therapy for resolution of symptoms. None of the reported symptoms were incapacitating and none of the aircraft involved crashed or received even minor damage.

Aerospace Medicine↗