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PubMed1995

[Incidence of dilatation of residual cystic duct in liver transplantation. Our experience with 152 cases].

In our series of patients, we studied the incidence of residual cystic duct mucocele, which is still considered a rare complication in orthotopic liver transplantation (OLT). 152 OLTs were performed in 138 patients in the II Surgery Dept. of Bologna University, May 1986 to June 1994; a termino-terminal choledocho-choledochal anastomosis was performed in 145 of them. A choledocho-jejunal anastomosis was performed in other 7 patients. In 3 patients we observed an anechoic ovoidal structure localized just before the portal vein, near the main bile duct (MBD). Then, we monitored the evolution of this finding by ultrasonography (US), Doppler US, CT and CT-cholangiography. Integrated imaging, clinical and surgical data, led to the diagnosis of non-obstructive mucocele of residual cystic duct in OLT. To date, this complication has not led, on our series, to the necessity of new surgical procedures for cholestasis by MBD compression, which is in disagreement with literature data. In our series, the incidence of residual cystic duct mucocele is 2%, which is a higher value than those reported in the literature, suggesting that this condition be investigated carefully as a non-rare complication in OLT.

Adult↗
PubMed2006

Balloon kyphoplasty for symptomatic vertebral body compression fractures results in rapid, significant, and sustained improvements in back pain, function, and quality of life for elderly patients.

STUDY DESIGN: Prospective, single-arm interventional cohort. OBJECTIVE: To evaluate the safety and effectiveness of balloon kyphoplasty to treat symptomatic vertebral body compression fractures (VCFs). SUMMARY OF BACKGROUND DATA: VCFs treated nonoperatively can diminish function and quality of life, and lead to chronic health effects. The short-term safety and effectiveness of balloon kyphoplasty for symptomatic VCFs are well-documented, but long-term follow-up is needed. METHODS: A total of 155 elderly patients with symptomatic VCFs were enrolled in a prospective, multicenter treatment study of balloon kyphoplasty at 19 geographically diverse US centers. Outcomes included back pain severity, bedrest, and limited activities because of back pain, back disability score, and SF-36 Medical Outcomes Survey, at 7 days (visual analog scale only), and 1, 3, 12, and 24 months after treatment. RESULTS: Patients reported severe back pain (15/20 on visual analog scale) interfering with daily activities 90% of days per month before kyphoplasty. Physical functioning and quality of life were also markedly impaired. Statistically significant (P < 0.001) improvements occurred in all pain, functional, and mental health outcomes at the first follow-up after treatment and were maintained for 24 months. CONCLUSIONS: Elderly patients with symptomatic VCFs had rapid, significant, and sustained improvements in back pain, back function, and quality of life following balloon kyphoplasty.

Aged↗
PubMed1994

Precise and limited decompression for lumbar spinal stenosis.

Fifty-eight consecutive patients with lumbosacral nerve root entrapment due to spinal stenosis were treated with modified microsurgical decompression. Only the clinically relevant sides and levels were decompressed while the spinous processes, the interspinous ligaments, the medial portion of ligamentum flavum and the functionally important parts of the facet joints were preserved. The reviewers rated recovery as good or excellent in 71% of patients while patient self-assessment indicated 76% good or excellent outcome. These data suggest that microsurgical decompression of spondyloarthritic changes can effectively relieve the signs and symptoms of nerve root compression and that with careful evaluation of all available data the number of nerve roots requiring decompression is often fewer than what is suggested by diagnostic images alone.

Adult↗
PubMed1995

Transoral anterior decompression and fusion of chronic irreducible atlantoaxial dislocation with spinal cord compression.

STUDY DESIGN: In this study, 10 patients with chronic irreducible atlantoaxial dislocation were treated by transoral anterior decompression and fusion. OBJECTIVES: To examine the benefits of the transoral approach, the patients treated with this procedure were compared with the historical control subjects after 2 years of follow-up. SUMMARY AND BACKGROUND DATA: Chronic irreducible atlantoaxial dislocation with cord compression is difficult to treat because the cord is compressed posteriorly by the posterior arch of the atlas as well as anteriorly by the posterior-superior portion of the axial body and nonunited dens. Its irreducibility, as a result of the bony scarring between the dens and the anterior body of the axis, and the locking of the lateral joints of C1-C2, makes reduction more complex. Posterior surgical approaches have been associated with high morbidity and mortality. METHODS: Ten patients were diagnosed and followed up by clinical symptoms, radiography, pantopaque myelography, and computed tomography. They were treated surgically by transoral decompression and fusion. During the surgery the nonunited dens as well as callus, granulation, and scar tissue were removed; the cartilage of the articular surfaces of the atlantoaxial joint was excised. Postoperative treatment included skull-cervical biaxial traction, tracheostomy care, nasal feeding, and Minerva cast. RESULTS: The 2- to 6-year follow-up showed that four out of 10 patients recovered completely and returned to work, three recovered to a great degree and ambulated, two partially recovered, and one recovered poorly. CONCLUSION: Transoral decompression and fusion offered satisfactory results in a series of patients with chronic irreducible atlantoaxial dislocation. None of the patients showed serious complications of stability, even though only one had a secondary posterior fusion. Therefore, anterior decompression associated with subtotal obliteration of the atlantoaxial joints without bone grafts is a feasible therapy for irreducible atlantoaxial dislocation using a multifunctional bed and biaxial traction.

Adolescent↗
PubMed2000

Compression bandages and stockings for venous leg ulcers.

OBJECTIVES: To assess the effectiveness and cost-effectiveness of compression bandaging and stockings in the treatment of venous leg ulcers. SEARCH STRATEGY: Searches of 19 databases, hand searching of journals, conference proceedings and bibliographies. Manufacturers of compression bandages and stockings and an Advisory Panel were contacted for unpublished studies. SELECTION CRITERIA: Trials that evaluated compression bandaging or stockings, as a treatment for venous leg ulcers. There was no restriction on date or language. Ulcer healing was the primary endpoint. DATA COLLECTION AND ANALYSIS: Details of eligible studies were extracted and summarised using a data extraction sheet. Data extraction was verified by two reviewers independently. MAIN RESULTS: Twenty two trials reporting 24 comparisons were identified. Compression was more effective than no compression (4/6 trials). When multi-layered systems were compared, elastic compression was more effective than non-elastic compression (5 trials). There was no difference in healing rates between 4-layer bandaging and other high compression multi-layered systems (3 trials). There was no difference in healing rates between elastomeric multi-layered systems (4 trials). Multi-layered high compression was more effective than single layer compression (4 trials). Compression stockings were evaluated in two trials. One found a high compression stocking plus a thrombo stocking to be more effective than a short stretch bandage. The second small trial reported no difference between the compression stockings and Unna's boot. There was insufficient data to draw conclusion about the relative cost-effectiveness of different regimens. REVIEWER'S CONCLUSIONS: Compression increases ulcer healing rates compared with no compression. Multi-layered systems are more effective than single-layered systems. High compression is more effective than low compression but there are no clear differences in the effectiveness of different types of high compression.

Bandages↗
PubMed1997

The cervical subluxation and regional cerebral blood flow.

OBJECTIVE: This article specifically addresses the question of whether the manipulable cervical lesion is likely to cause extrinsic compression of the vertebral arteries sufficient to cause such symptoms of reduced regional cerebral blood flow as might be relieved by spinal manipulation. DATA SOURCES: Literature on normal and abnormal cerebral circulation, including vertebrobasilar insufficiency. DATA SYNTHESIS: Signs and symptoms produced by extrinsic compression of the vertebrobasilar system have been compared with those attributed elsewhere to the manipulable cervical lesion (cervical subluxation). RESULTS: Extrinsic compression of the vertebrobasilar system generally does not produce signs and symptoms consistent with those attributed to the manipulable cervical lesion. CONCLUSION: It has been hypothesized elsewhere that the manipulable cervical lesion may induce localized decreases in regional cerebral blood flow, and so signs and symptoms attributable to "cerebral hibernation." If a causal relationship does exist between the cervical subluxation and reduced regional cerebral blood flow, it is not likely to be caused by mechanical compression of the vertebral arteries.

Animals↗
PubMed1997

Biomechanical implications of mineral content and microstructural variations in cortical bone of horse, elk, and sheep calcanei.

BACKGROUND: Artiodactyl and perissodactyl calcanei have been recently introduced as models for examining bone for mechanically mediated adaptation. We have reported substantial regional variations in cortical bone microstructure and mineral content within the same cross-section of mule deer calcanei. In part, these variations may be adaptations accommodating the customary presence of predominantly tension, compression, and shear strain modes in mutually exclusive cortical locations. Calcanei from skeletally mature horses, elk, and sheep were examined in order to corroborate these previous findings. METHODS: From each species, one calcaneus was obtained from each of 13 animals. Each bone was cut transversely near mid-shaft into two segments and examined for mineral (ash) content. From each species, an additional segment obtained from each of 7 of the original 13 bones was examined for microstructure using 50x backscattered electron images. Regions examined included the compression (cranial), tension (caudal), and medial and lateral (shear) cortices. Periosteal (P), middle (M), and endosteal (E) regions were also examined separately within the compression and tension cortices. Quantified microstructural parameters included: (1) secondary osteon population density (OPD), (2) fractional area of secondary bone (FASB), (3) porosity, (4) population density of new remodeling events (NRE = resorption spaces and newly forming secondary osteons), and (5) secondary osteon diameter and minimum-to-maximum chord ratio. RESULTS: Results in each species showed variations that are considered to be mechanically important and are similar to those reported in mule deer calcanei. Mineral content data suggest that remodeling activity in the compression, medial, and lateral cortices was occurring at a slower rate than remodeling in the tension cortex. In comparison to the tension cortices, the compression cortices have approximately 6.0% higher mineral content (P < 0.007) and 35% higher OPD (P < 0.01). Additionally, the compression cortices have more nearly perfectly round osteons and lower FASB, porosity, NRE, and osteon diameter (P < 0.05; except for FASB in horse where P = 0.087 and NRE in sheep where P = 0.520). However, patterns of microstructural variations between intracortical regions (P, M, E) are inconsistent when compared to data reported in mule deer calcanei. Microstructural characteristics between the medial and lateral cortices were similar although some significant differences were identified. In general, the microstructure of the medial and lateral cortices differ from the neighboring compression and tension cortices. CONCLUSIONS: Differences in mineral content and microstructure between opposing compression and tension cortices of these three species resemble differences previously reported in mule deer calcanei. The majority of the microstructural variations can be explained in the context of strain-magnitude-based rules of Frost's Mechanostat Theory of mechanically induced bone adaptation. These variations may also be strongly influenced by the strain mode predominating in each cortical location. The hypothesis that intracortical material adaptations are correlated with progressive transcortical strain magnitude variations is not supported by the inconsistent transcortical variations in material organization. These interpretations do not preclude the possibility that other specific strain features may contribute to a complex adaptive signal.

Animals↗
PubMed2005

Chest compression rates during cardiopulmonary resuscitation are suboptimal: a prospective study during in-hospital cardiac arrest.

BACKGROUND: Recent data highlight a vital link between well-performed cardiopulmonary resuscitation (CPR) and survival after cardiac arrest; however, the quality of CPR as actually performed by trained healthcare providers is largely unknown. We sought to measure in-hospital chest compression rates and to determine compliance with published international guidelines. METHODS AND RESULTS: We developed and validated a handheld recording device to measure chest compression rate as a surrogate for CPR quality. A prospective observational study of adult cardiac arrests was performed at 3 hospitals from April 2002 to October 2003. Resuscitations were witnessed by trained observers using a customized personal digital assistant programmed to store the exact time of each chest compression, allowing offline calculation of compression rates at serial time points. In 97 arrests, data from 813 minutes during which chest compressions were delivered were analyzed in 30-second time segments. In 36.9% of the total number of segments, compression rates were <80 compressions per minute (cpm), and 21.7% had rates <70 cpm. Higher chest compression rates were significantly correlated with initial return of spontaneous circulation (mean chest compression rates for initial survivors and nonsurvivors, 90+/-17 and 79+/-18 cpm, respectively; P=0.0033). CONCLUSIONS: In-hospital chest compression rates were below published resuscitation recommendations, and suboptimal compression rates in our study correlated with poor return of spontaneous circulation. CPR quality is likely a critical determinant of survival after cardiac arrest, suggesting the need for routine measurement, monitoring, and feedback systems during actual resuscitation.

Aged↗
PubMed2002

A dynamic 3D biomechanical evaluation of the load on the low back during different patient-handling tasks.

The objective of this study was to investigate the low-back loading during common patient-handling tasks. Ten female health care workers without formal training in patient handling performed nine patient-handling tasks including turning, lifting and repositioning a male stroke patient. The low-back loading was quantified by net moment, compression, and shear forces at the L4/L5 joint, measured muscle activity (EMG) in erector spinae muscles and rate of perceived exertion (RPE; Borg scale). The experiments were videotaped with a 50Hz video system using five cameras, and the ground and bedside reaction forces of the health care worker were recorded by means of force platforms and force transducers on the bed. The biomechanical load was calculated using a dynamic 3D seven-segment model of the lower part of the body, and the forces at the L4/L5 joint were estimated by a 14 muscles cross-sectional model of the low back (optimisation procedure). Compression force and torque showed high task dependency whereas the EMG data and the RPE values were more dependent on the subject. The peak compression during two tasks involving lifting the patient (4132/4433N) was significantly higher than all other tasks. Four tasks involving repositioning the patient in the bed (3179/3091/2932/3094N) did not differ, but showed higher peak compression than two tasks turning the patient in the bed (1618/2197N). Thus, in this study the patient-handling tasks could be classified into three groups-characterised by lifting, repositioning or turning-with different levels of peak net torque and compression at the L4/L5 joint.

Adult↗
PubMed2000

[Transrectal ultrasonography in the early diagnosis of prostate carcinoma: use of a new ultrasonography technique with endorectal probe].

Seventy-80% of prostatic carcinoma develops in the peripheral gland. Transrectal ultrasound (TRUS) has the capacity to identify nodules or hypoechogenic areas in the peripheral zone, suspected to be carcinoma. We describe a new echographic technic with endorectal probe (target compression test), to study hypoechogenic areas or nodules in the peripheral gland, during TRUS examination. Thirty-three patients, aged 49-77 years, with prostatic peripheral hypoechoic lesion at transrectal ultrasound, were studied. All patients underwent prostatic biopsy. Ten of the 11 positive patients (non compressible lesion) at the target compression test resulted to be affected by adenocarcinoma. Only 3 of the 22 negative patients (compressible lesion) at the target compression test resulted to be affected by adenocarcinoma. Even if our data have to be confirmed by further studies, they suggest that the target compression test may be a useful complementary test, during TRUS, in the evaluation of hypoechogenic areas in the peripheral gland.

Aged↗
PubMed1996

Long distance transmission of diagnostic cardiovascular information.

Availability of advanced cardiac diagnostic procedures has proven to decrease the morbidity and mortality associated with common cardiovascular diseases. It was requested that the University of Nebraska Medical Center (UNMC) provide a rural hospital with advanced cardiology services. The services included monitoring of inpatients and rapid interpretation of cardiac diagnostic tests. UNMC proposed to solve this problem by building a computer-based system to transmit diagnostic cardiac information from a rural hospital to UNMC for interpretation by a cardiologist. The information transmitted to UNMC was grouped into two categories: 1) cardiovascular ultrasound, 2) ambulatory and 12-lead electrocardiograms. The information consisted of digital and analog waveform information, static images, and 30 fps video. The system provided rapid data transmission to UNMC over a T-1 line. The system utilized a compression technology which did not degrade the interpretation quality of the data. This system has increased the availability of advanced cardiac diagnostic services to general medical practitioners in a rural hospital. In addition, the system has significantly reduced the time and cost to transmit vital cardiac diagnostic information, thus improving the quality of care received by rural patients.

Cardiovascular Diseases↗
PubMed1987

[Morphology and pathogenetic problems of the crush syndrome].

Morphofunctional studies of muscles, heart, liver and kidneys after different periods of compression and decompression, as well as literature data indicate that crush syndrome is one of the most severe forms of traumatic shock. A wide range of pathologic effects of catecholamines and other shock-causing agents in response to the emotional stress and pain occurs already at the compression period and results in hemodynamic disturbances in microcirculation of organs and tissues with the development of dystrophic and necrobiotic processes, depression of the monocytic phagocyte system and immune system. The consequences of shock are mostly manifest after decompression: hypercatecholaminemia, hypovolemia, intoxication with myolysis and pathogenic microflora products result in aggravation of monocytic phagocyte failure, as well as immune system, intravascular coagulation, membrane penetration insufficiency, cell necrosis. Monocytic macrophage depletion favours the progression of hepatic necrobiosis, formation of renal failure and detritus organization in the muscles of the extremities. Hypercatecholaminemia and hypoxia (leading to electrolyte-imbalance contractures of myofibrillar apparatus, metabolism disorder and intracellular conductivity disturbance) from the basis for cardiac insufficiency. Inadequate cardiac function, in its turn, maintains hemodynamic and hypoxic disturbances in tissues. Changes in renal blood flow, hemofiltration and tubular system are shown to reflect different aspects of pathogenesis of the acute renal failure in crush syndrome.

Animals↗
PubMed2004

Mechanics considerations for microporous titanium as an orthopedic implant material.

This article investigates mechanics issues related to potential use of a recently developed porous titanium (Ti) material for load-bearing implants. This material may have advantages over solid Ti of enhancing the bone-implant interface strength by promoting bone and soft tissue ingrowth and of reducing the bone-implant modulus mismatch, which can lead to stress shielding. Experimental data from ultrasound experiments and uniaxial compression testing on microporous Ti are presented. Analytic models to predict its elastic modulus and Poisson's ratio are discussed, including "structural" approaches (Gibson and Ashby's cellular solids) and a "composite material" approach (Mori-Tanaka). Finally, two-dimensional finite element models based on optical micrographs of the material are presented. Simulations were performed for different conditions and levels of approximation. Results demonstrate that simple analytic models provide good estimates of the elastic properties of the porous Ti and that the moduli can be significantly reduced to decrease the mismatch between solid Ti and bone. The finite element simulations show that bone ingrowth will dramatically reduce stress concentrations around the pores.

Biomechanical Phenomena↗
PubMed2001

Focal cooling improves neuronal conduction in peroneal neuropathy at the fibular neck.

Heat can induce conduction block (CB) in demyelinated neurons; whether cooling can reverse CB and increase strength is uncertain. In six patients with electrophysiologic evidence of peroneal neuropathy at the fibular neck with definite motor CB, standard motor nerve conduction studies were performed at 32 degrees C and then after the fibular neck region was cooled with an ice pack to 8 degrees -12 degrees C. In all patients, cooling increased the amplitude and area of the compound motor action potential obtained with popliteal fossa stimulation, decreasing the relative amplitude drop across the fibular neck from a mean of 78% to 55%. A concomitant increase in foot dorsiflexor strength was clearly observed in three of the six patients. Both the electrophysiologic and clinical changes readily reversed upon rewarming. These data support the belief that, in compressive neuropathies, cooling relieves conduction block in selected motor neurons, improving strength.

Action Potentials↗
PubMed1986

Bone modeling during growth: dynamic strain equilibrium in the chick tibiotarsus.

Bone loading was quantified, using in vivo strain recordings, in the tibiotarsus of growing chicks at 4, 8, 12, and 17 weeks of age. The animals were exercised on a treadmill at 35% of their maximum running speed for 15 minutes/day. In vivo bone strains were recorded at six sites on the tibiotarsus. Percentages of the bone's length and a percentage of top running speed were used to define functionally equivalent sites on the bone, and a consistent exercise level over the period of growth was studied. The pattern of bone strain defined in terms of strain magnitude, sign, and orientation remained unchanged from 4-17 weeks of age, a period when bone mass and length increased 10-fold and threefold, respectively. Our findings support the hypothesis that bones model (and remodel) during growth to achieve and maintain a similar distribution of dynamic strains at functionally equivalent sites. Because strain magnitude and sign (tensile versus compressive) differed among recording sites, these data also suggest that cellular responses to strain-mediated stimuli differ from site to site within a bone.

Animals↗
PubMed2000

A comparison of two methods of analog-to-digital medical video conversion.

The purpose of this study was to compare 2 methods of analog-to-digital video conversion in anticipation of improving, refining, and standardizing digital video production for medical education, diagnosis support, and telemedicine. A video workstation was devised containing 2 analog-to-digital video conversion systems: a digital video media converter with fire wire card and a video capture card. A procedure for final digital video production was created that used equivalent compression, pixel resolution, frame rate, and data rate for both systems. A subjective test was performed in which 12 archived analog videotapes, consisting of magnetic resonance angiograms, ultrasounds, neurosurgeries, and telemedicine applications, were converted digitally using the 2 methods. Randomized side by side video comparisons were analyzed and rated by subjective quality. An objective test was performed by videotaping a gray-scale test pattern off a computer monitor, digitally converting it by the 2 methods, and comparing the gray-scale values to the original pattern. There was no significant difference in overall video quality (P = .31) or grayscale reproduction using the 2 methods of analog-to-digital conversion. When performing simple analog-to-digital video conversion, a video capture card is equal in quality and costs less than a digital video (DV) media converter or fire wire card. If a digital video camera is available for use, then a DV media converter or fire wire card is more advantageous because it enables full operation of the digital video camera.

Analog-Digital Conversion↗
PubMed2005

Basic fibroblast growth factor improves trabecular bone connectivity and bone strength in the lumbar vertebral body of osteopenic rats.

Recently, basic fibroblast growth factor (bFGF) has been found to increase trabecular bone mass and connectivity in the proximal tibial metaphyses (PTM) in osteopenic rats. The purpose of this study was to determine the bone anabolic effects of bFGF in the lumbar vertebral body (LVB), a less loaded skeletal site with a lower rate of bone turnover than the PTM. Six-month old female Sprague-Dawley rats were ovariectomized (OVX) or sham-operated and untreated for 8 weeks to induce osteopenia. Then group 1 (sham) and group 2 (OVX) were treated subcutaneously (s.c.) with vehicle, and OVXed groups 3 and 4 were treated s.c. with PTH [hPTH (1-34) at 40 microg/kg, 5x/week] and bFGF (1 mg/kg, 5x/week), respectively, for 8 weeks. At sacrifice, the fifth LVB was removed, subjected to micro-CT for determination of trabecular bone structure and then processed for histomorphometry to assess bone turnover. The sixth LVB was used for mechanical compression testing (MTS, Bionix 858). The data were analyzed with the Kruskal-Wallis test followed by post-hoc testing as needed. After 16 weeks of estrogen deficiency, there were significant reductions in vertebral trabecular bone volume and trabecular thickness. Treatment with either bFGF or hPTH (1-34) increased BV/TV in OVX animals. Human PTH (1-34)-treated animals had significant increases in trabecular (48%) and cortical thickness (30%) and bone strength [maximum load (53%) and work to failure (175%)] compared to OVX + Vehicle animals. Treatment of osteopenic rats with bFGF increased bone volume (15%), trabecular thickness (13%), maximum load (45%) and work to failure (140%) compared to OVX + Vehicle animals (all P <0.05). Basic FGF increased trabecular bone volume in the lumbar vertebral body of osteopenic rats by restoring trabecular number, thickness and connectivity density. Also, bFGF improved bone mechanical properties (maximum force and work to failure) compared to the OVX + Vehicle group. Therefore, increasing the number, thickness and connections of the trabeculae contributes to increased bone strength in this small animal model of osteoporosis.

Animals↗
PubMed2005

[Compression therapy in the treatment of acute deep vein thrombosis].

Especially in Europe patients with acute deep vein thrombosis (DVT) of the leg are treated with compression therapy. A look at the literature, however, reveals that the exact mechanism of compression therapy in the treatment of acute deep vein thrombosis is not completely understood. Effects on fibrinolysis, resolution of pain and swelling as well as a fixation of the thrombus towards the vessel wall have been discussed. The literature indicates that compression stockings were mostly used in the treatment of DVT although there is some evidence that inelastic compression bandages have a greater impact on resolution of swelling and pain. Large randomised multicenter trials are still not available. Furthermore, evidence-based data providing an advantage of thigh-length compression therapy in the treatment of acute DVT are lacking. Studies have, however, shown that compression therapy is a safe therapy and can reduce the development of postthrombotic syndrome after acute DVT.

Acute Disease↗