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PubMed1979

Changes in ultrasonic attenuation indicative of early myocardial ischemic injury.

This study was designed to determine whether quantitative alterations in ultrasonic attenuation are associated with myocardial changes occurring after acute ischemic injury. Five hundred seventeen regions of myocardium from 41 dogs were studied in vitro at five intervals after coronary occlusion: 15 min, 1 h, 6 h, 24 h, 3 days, and 6 wk. Quantitative indices of ultrasonic attenuation were determined from the measured frequency dependence of the ultrasonic attenuation coefficient characterizing each myocardial region over the range 2-10 MHz. Independent definition of regions of ischemic injury was provided by either creatine kinase depletion or colloidal carbon dye distribution. Results of this study indicate that ischemic myocardial regions investigated 15 min to 24 h after coronary occlusion demonstrated ultrasonic attenuation significantly decreased from nonischemic regions (P less than 0.05). In contrast, ultrasonic attenuation was significantly increased in zones of ischemia or infarction investigated at 3 days and 6 wk after coronary occlusion (P less than 0.05 and P less than 0.01, respectively). These results indicate that altered attenuation of transmitted ultrasound by myocardium in vitro is an early manifestation of ischemia.

Animals↗
PubMed2000

Differential impact of ultrasonically nebulized versus tracheal-instilled surfactant on ventilation-perfusion (VA/Q) mismatch in a model of acute lung injury.

In a model of acute lung injury, established by saline lavage of isolated perfused rabbit lungs, the effect of ultrasonic surfactant nebulization on gas exchange was compared with that of tracheal instillation, assessed by the multiple inert gas elimination technique (MIGET). Ultrasonic aerosolization provided particles with a mass median aerodynamic diameter of 4.5 microm (geometric SD, 2.3), the pulmonary deposition of which was monitored on-line by a laserphotometric technique. Under baseline conditions, a narrow unimodal distribution of ventilation and perfusion with shunt-flow ranging below 2% and absence of perfusion of low V A/Q (0.01 < V A/Q < 0.1) areas was noted throughout. This physiological V A/Q matching was not affected by lung deposition of 8.6 mg surfactant/kg body weight (bw), forwarded by 1 h ultrasonic nebulization. In contrast, tracheal bolus injection of 80 mg/ kg bw surfactant in control lungs provoked the appearance of low V A/Q areas (maximum approximately 13% of perfusion) and shunt flow (4 to 6%), in addition to marked ventilation-perfusion mismatch (broadening of perfusion and ventilation distribution) in the midrange V A/Q regions. The saline lavage procedure caused progressive development of shunt flow ( approximately 22%) and perfusion of low V A/Q areas ( approximately 7%), associated with severe V A/Q mismatch. "Rescue" tracheal instillation of 80 mg/kg bw surfactant in lavaged lungs reduced the shunt-flow to approximately 4%, but increased the perfusion of low V A/Q areas to 10 to 14%; V A/Q mismatch in the midrange V A/Q regions was not improved. Ultrasonic deposition of 8.8 mg surfactant/kg bw in the injured lungs reduced the shunt flow to approximately 7% and the perfusion of low V A/Q areas to < 2%, coincident with improvement of V A/Q matching in the midrange V A/Q areas. We conclude that low doses of ultrasonically delivered natural surfactant are similarly effective as "conventional" doses of tracheal-instilled surfactant in reducing shunt flow in an acute lung injury model, but exert more advantageous effects on ventilation perfusion matching.

Administration, Inhalation↗
PubMed2003

Anterior clinoidectomy and opening of the internal auditory canal using an ultrasonic bone curette.

OBJECTIVE: During cranial base surgery, use of a high-speed drill for osteotomy has become common. We performed anterior clinoidectomy and opening of the internal auditory canal using an ultrasonic bone curette, and we report the advantages and clinical applications of this method. DESCRIPTION OF INSTRUMENTATION: The ultrasonic surgical equipment comprises a power supply unit, footswitch, and handpiece (weight, 110 g; diameter, 20 mm; length, 140 mm from tip to angled section). The handpiece tip is 2 mm wide, and the amplitude of longitudinal vibration can be varied from 120 to 365 microm at an ultrasonic frequency of 25 kHz. Cool-controlled irrigation fluid emerges near the tip, through the sheath. EXPERIENCE AND RESULTS: We performed anterior clinoidectomy in eight cases of paraclinoid aneurysm and opening of the internal auditory canal in six cases of acoustic neuroma without damage to the dura mater or nearby structures such as brain tissue, blood vessels, and cranial nerves. In addition, no damage to the facial nerve or labyrinthine organ resulted from heat or vibration caused by the ultrasonic bone curette. CONCLUSION: Ultrasonic bone curettage represents safe instrumentation for performance of anterior clinoidectomy and opening of the internal auditory canal without damage to surrounding structures. This technique allows surgeons to perform procedures on deep areas without incurring psychomotor stress.

Craniotomy↗
PubMed2005

Use of ultrasonic aspiration for dural opening in cranial reoperations: technical note.

OBJECTIVE: Dural detachment from the brain in cranial reoperations has been accomplished previously by selective coagulation and the cutting of brain-dural adhesions. The results of ultrasonic aspiration during tumor surgery or brain cutting procedures led the authors to speculate that the detachment of the dura mater from brain tumors by applying the Cavitron ultrasonic surgical aspirator (Valleylab, Boulder, CO [formerly Cavitron, Inc., Stamford, CT]) to the brain-dura mater interface could be used to reduce bleeding and facilitate dural opening during cranial reoperations. METHODS: Ten patients underwent a second craniotomy for epilepsy surgery (five cases of extended temporal lobectomy and five cases of extended extratemporal lesionectomy). The use of ultrasonic aspiration and its effects on brain separation from the dura mater were examined. RESULTS: Intraoperative use of the Cavitron ultrasonic surgical aspirator during dural opening produced immediate blanching of the dura mater and enhanced visualization of the cortical surface without distortion of the brain anatomy. CONCLUSION: Incremental dural opening and brain visualization is achieved by careful application of ultrasonic aspiration directly into the brain-dura limit, producing immediate regional dural devascularization. Use of this technique reduces cortical and dural bleeding and enhances the ease and effectiveness of brain visualization.

Dura Mater↗
PubMed1977

Clinical assessment of analgesics using ultrasonic stimulation. A new method.

A quantitative method for measuring pain threshold by the use of ultrasonic stimulation in man was designed and the possibility of clinical application in assessing analgesics was investigated. Ultrasonic stimulus was given to Japanese subjects on the palmer distal part of the 2nd, 3rd and 4th fingers of both hands. The latent time between start of the stimulation and withdrawal of the hand when perceiving pain was considered the pain threshold. The ultrasonic evoked pain was a sharp pin-prick type, without sensations such as thermal and mechanical. The pain threshold lowered with increasing either stimulus intensity or water bath temperature when the hand of the subject was immersed during measurement. Normal threshold to ultrasonic stimulation measured in both 50 men and 50 women gave nearly normal distribution curves; women being more sensitive to ultrasonics than men. Analgesia with codeine phosphate (20 mg p.o.), aspirin (1.5, 1.0, 0.5 g p.o.), aminopyrine (100 mg p.o.) and mefenamic acid (500 mg p.o.) in volunteers of both sexes was demonstrated significantly using this method under double blind circumstances. Pentobarbital, diazepam, butylscopolamine, bromelain and placebo each in the usual dose used clinically failed to alter the pain threshold. Humans were at least 25 fold more sensitive than mice to the analgesics used herein.

Adolescent↗
PubMed2006

Ultrasonic storage modulus as a novel parameter for analyzing protein-protein interactions in high protein concentration solutions: correlation with static and dynamic light scattering measurements.

The purpose of this work was to establish ultrasonic storage modulus (G') as a novel parameter for characterizing protein-protein interactions (PPI) in high concentration protein solutions. Using an indigenously developed ultrasonic shear rheometer, G' for 20-120 mg/ml solutions of a monoclonal antibody (IgG(2)), between pH 3.0 and 9.0 at 4 mM ionic strength, was measured at frequency of 10 MHz. Our understanding of ultrasonic rheology indicated decrease in repulsive and increase in attractive PPI with increasing solution pH. To confirm this behavior, dynamic (DLS) and static (SLS) light scattering measurements were conducted in dilute solutions. Due to technical limitations, light scattering measurements could not be conducted in concentrated solutions. Mutual-diffusion coefficient, measured by DLS, increased with IgG(2) concentration at pH 4.0 and this trend reversed as pH was increased to 9.0. Second virial coefficient, measured by SLS, decreased with increasing pH. These observations were consistent with the nature of PPI understood from G' measurements. Ultrasonic rheology, DLS, and SLS measurements were also conducted under conditions of increased ionic strength. The consistency between rheology and light scattering analysis under various solution conditions established the utility of ultrasonic G' measurements as a novel tool for analyzing PPI in high protein concentration systems.

Biophysics↗
PubMed1998

Ontogenetic changes in responsiveness to benzodiazepine receptor ligands on ultrasonic vocalizations in rat pups.

The ontogenetic changes in responsiveness to benzodiazepine receptor ligands on ultrasonic vocalizations in rat pups from the age of day 3 to day 12 were evaluated. Rat pups, while separated from their dam and littermates and placed in a cold environment, emit ultrasonic vocalizations. These ultrasonic calls became attenuated dose-dependently in number and power after administration of the anxiolytic diazepam (0.25-1.0 mg/kg, s.c.), but the inhibitory effect of diazepam at the highest dose was less on day 6 and day 9. Moreover, type 1 benzodiazepine receptor ligands, Ro16-6028 and Ro23-0364 (0.5-2.0 mg/kg, s.c.), also dose-dependently attenuated the ultrasonic vocalizations 30-60 min after injection. The inhibitory effects of these drugs became more pronounced with the increasing age of the pup, and they were equivalent on day 12 to those in adult rats. These results suggest that different ontogenetic changes in development of two subtypes of central benzodiazepine receptors of pups might be related in the psychopharmacological mediation of the ultrasonic vocalization.

Animals↗
PubMed2001

In vitro characteristics of tobramycin aerosol from ultrasonic and jet nebulizers.

STUDY OBJECTIVE: To compare the in vitro performance of an ultrasonic nebulizer and a jet nebulizer in producing a respirable aerosol of tobramycin solution for injection. DESIGN: In vitro observational study DEVICES: Ultrasonic and jet nebulizers. INTERVENTION: Output was determined by measuring the difference in nebulizer weight before and after nebulizing 3 ml of tobramycin injection solution. Mass median aerodynamic diameter (MMAD) and respirable mass were determined by sampling tobramycin aerosol into a cascade impactor. MEASUREMENTS AND MAIN RESULTS: Mean (SD) output was 1.14 (0.09) ml/minute for the ultrasonic nebulizer and 0.64 (0.08) ml/minute (p<0.001) for the jet nebulizer. Mean MMAD for the jet nebulizer (2.31 [0.10] microm) was less than that of the ultrasonic nebulizer (2.81 [0.17] microm, p<0.001). The majority of tobramycin aerosol produced was in the respirable range for both the ultrasonic (65.1% [4.10%]) and jet (60.6% [0.73%], p=0.008) nebulizers. CONCLUSION: Despite small, clinically unimportant differences in aerosol size and respirable fraction, either device would be acceptable to administer tobramycin injection solution.

Aerosols↗
PubMed2001

Investigation and development of ultrasonic vibrodrives for traumatology.

An investigation was made of the dynamics of ultrasonic vibrodrills with a common source of rotational and ultrasonic reciprocal motions. The source was constructed on the basis of an electroacoustic transducer of longitudinal vibrations. The dependences of power, rotation speed, and flutter rates were plotted for various pushers as a function of biological tissue drag torque. The results obtained allowed us to determine the optimal parameters of basic ultrasonic modes used in treating biological tissues. Apart from that, ultrasonic vibrodrill pilot models, which are new in principle, are presented. They were designed to be applied in traumatology. A distinguishing feature of these vibrodrills is that an electroacoustic transducer of longitudinal vibrations is a source of two motion types: rotational and ultrasonic reciprocal.

Equipment Design↗
PubMed1980

Postsurgical bone loss following root planing by ultrasonic and hard instruments.

The ultrasonic scaler is currently used to plane the roots in periodontal surgery. The purpose of this study was to provide experimental evidence in support of, or against, the use of the ultrasonic scaler for root planning in periodontal surgical procedures. A notch was made through the enamel of each canine of nine adult cats. Full thickness mucoperiosteal flaps were elevated on each canine. Using hand curettes, soft tissue tags were removed from each tooth. At the maxillary right canines and mandibular left canines the roots were planed using the ultrasonic scaler, while at the maxillary left canines and mandibular right canines the roots were planed using hand curettes. A caliper was used to measure the distance from the notch to the crest of the alveolar process at each tooth. The mucoperiosteal flaps were repositioned and secured with cyanoacrylate cement. Three months postoperatively all 36 sites were reoperated and the distance from the notch of each canine to the crest of its alveolar process was measured using the caliper. The same caliper was used for all sites and the same investigator made all the measurements. Analysis of the results showed that all canines lost alveolar bone as a result of the surgical procedure, however, there was no statistical significance between the amount of bone lost on the canines where root planing was carried out by the ultrasonic scaler and the canines where the roots were planed with hand curettes. These findings support the use of the ultrasonic scaler for the planing of roots following elevation of mucoperisteal flaps and confirm its value in the practice of periodontal surgical procedures.

Alveolar Process↗
PubMed1984

The effectiveness of hand versus ultrasonic instrumentation in open flap root planing.

The primary purpose of the study was to determine if, with an open flap approach, ultrasonic or hand instrumentation could remove all calculus from previously untreated teeth with moderate to severe loss of attachment. To be included in the study, teeth had to have at least 5 mm of attachment loss, be scheduled for extraction and be graded 2 or 3 on the Calculus Index of the Periodontal Disease Index system. Under local anesthesia, full-thickness, envelope-type flaps were elevated apical to the crest of bone to allow access to the root surfaces which were then treated with hand or ultrasonic instrumentation until the roots felt hard and smooth to a Hartzell explorer. The teeth were then removed, rinsed, and lightly scrubbed to remove debris and a No. 14 wheel bur was used to place a groove along the coronal extent of the connective tissue attachment. A stereomicroscope at magnification X 4.6 was used to quantitate the percentage of residual calculus on 25 teeth treated by each method. Overall, hand-scaled root surfaces demonstrated less residual calculus (5.78%) than ultrasonically treated surfaces (6.17%). Twenty teeth treated by each method were then prepared for histologic evaluation and evaluated under the light microscope at magnification X 100 for residual calculus and relative smoothness. Residual calculus was found on four ultrasonically and 12 hand-treated teeth and was almost evenly distributed between anterior and posterior teeth for both methods. The finding of considerably less calculus on histologic than on stereomicroscopic examination may have been due to the loosening of deposits by instrumentation, especially ultrasonic vibration, and their subsequent release during histologic preparation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

In vitro effectiveness of a newly-designed ultrasonic scaler tip for furcation areas.

This study was undertaken to perform an in vitro comparison of the accessibility and effectiveness of a newly-designed furcation tip for an ultrasonic system with conventional curets and ultrasonic scalers. The new furcation tip was spiral in shape with a spherical end. The study was conducted on three groups of 40 teeth, each comprising 20 maxillary and 20 mandibular molars. The furcation of each tooth was colored by black felt-tipped marker, after which the teeth were fixed into artificial jaw models. Each group was then instrumented by either the newly-designed furcation tip, a straight type ultrasonic scaler tip, or a Gracey curet. The teeth were photographed by a stereomicroscope from the dome surface of furcation, and the percentage of remaining colored area was calculated for each tooth. Replica models were also made and examined with scanning electron microscopy (SEM). The mean percentage of the remaining colored areas for each instrument was, for the maxillary molars and mandibular molars respectively, 15.1% and 16.7% with the newly-designed tip; 50.3% and 44.1% with the straight type ultrasonic scaler; and 61.1% and 39.5% with the Gracey curets. The newly-designed tip thus showed high levels of effectiveness and accessibility for furcation debridement. Although the SEM photographs showed that each instrument had affected the furcation surfaces in various degrees, the teeth instrumented by the newly-designed tip maintained relatively smoother surfaces. It was concluded that the newly-designed furcation tip was more effective than the straight type ultrasonic scaler or the Gracey curet in the debridement of furcation in vitro.

Dental Plaque↗
PubMed1989

A scanning electron micrographical study of root surfaces and subgingival bacteria after hand and ultrasonic instrumentation.

The effects of hand and ultrasonic instrumentation on root surface topography and subgingival plaque were studied. One approximal subgingival root surface on each of two single rooted teeth of six patients was root planed. The opposing proximal surfaces were not treated and served as controls. On each patient, the two test surfaces were randomly treated by hand or ultrasonic instrumentation (Cavitron) until clinically smooth. The teeth were extracted, divided into mesial and distal sides, and processed for scanning electron microscopy (SEM). The observations were restricted to an area 2 mm by 3 mm just coronal to the plaque-free zone. The root surfaces were scanned by SEM, both at low (x 100) and at higher magnifications (x 5000). At low power, a photomontage was produced of the surface area of the test teeth. At low magnifications (x 100, x 500), the topography resulting from hand instrumentation appeared smooth with parallel scratches compared to scaly but flat surfaces with occasional deep gouges with the ultrasonic method. At high magnifications (x 5000), tooth surfaces were similar in topography when instrumented by either hand or ultrasonic methods. Root surfaces were covered in some areas by a fibrillar-like membrane that resembled fibrin. Individual bacteria were found on the surfaces of this material. On other areas not covered by this membrane, bacterial plaque was only observed when tooth surfaces had not been contacted by either hand or ultrasonic instrumentation.

Aged↗
PubMed1997

Clinical evaluation of the speed and effectiveness of subgingival calculus removal on single-rooted teeth with diamond-coated ultrasonic tips.

Several studies have found incomplete calculus removal during periodontal treatment with traditional hand curets, sonic, and ultrasonic instruments. This study evaluated the speed and effectiveness of subgingival calculus removal with new diamond-coated ultrasonic tips on single-rooted teeth. Single session subgingival scaling and root planing was performed on 80 teeth with 5 to 12 mm probing depths in 15 patients. Each patient provided groups of 4 teeth that were randomly treated with either hand curets (HAND); standard smooth ultrasonic tip (US); or fine grit (FINDIAM) or medium grit (MEDDIAM) diamond-coated ultrasonic tips. The time taken to reach the therapeutic endpoint of a clean, smooth root surface in a defined region on each tooth with each instrument by the 3 therapists with differing experience levels was recorded. The teeth were then atraumatically extracted, stored in a surfactant, photographed at 10X, and the percent of calculus present in the area of the pocket or on a comparable control surface calculated by histometric point counting. ANOVA and paired t tests showed that mean percent remaining calculus on treated versus control surfaces was HAND 4.6 +/- 5.3 versus 57.5 +/- 28.2, US 4.7 +/- 6.4 versus 54.4 +/- 25.9, FINDIAM 4.3 +/- 5.2 versus 37.5 +/- 22.1, and MEDDIAM 3.4 +/- 4.2 versus 50.7 +/- 20.1, respectively (all P < 0.01). The mean time in seconds to reach the clinical endpoint ranged from HAND 289 +/- 193, US 194 +/- 67, FINDIAM 167 +/- 71, to MEDDIAM 147 +/- 92. All powered instruments were significantly faster than HAND (P < 0.05), but did not differ from each other. On a 0 = "smooth" to 3 = "rough" scale, most often HAND resulted in "smooth" surfaces (10/20), the powered tips of all types "slight" surface roughness (10/20 each), and US the most "moderate" roughness (7/20). There were no differences in percent calculus remaining, surface roughness, or time spent among the 3 treating clinicians despite their varying experience levels. The results of this study showed that percent calculus remaining was <5% with all the instruments given time ad libitum on a given root surface. Root roughness was generally slightly greater with all 3 powered tips. All of the powered instruments took significantly less time than the HAND. Both DIAM tips took less time than US. Diamond-coated ultrasonic tips appeared to be much more efficient than HAND or US in removing calculus in moderate-deep probing depths on single-rooted teeth in vivo.

Adult↗
PubMed1999

Acoustic microstreaming: detection and measurement around ultrasonic scalers.

BACKGROUND: Acoustic microstreaming (AMS) may be useful to the clinician when using the ultrasonic scaler to remove particulate matter from the teeth. The aim of this study was to detect and measure the effects of AMS produced by ultrasonic scalers. METHODS: For the study, an ultrasonic generator was selected with 4 differently shaped scaling tip inserts (TFI-3, TFI-9, TFI-1, and P-12). A plaque substitute (0.2 mm thick soft cream cheese) was coated onto a microscope slide and immersed in water. The ultrasonic scaler tip was placed in the water and orientated either perpendicular or parallel to the slide. The instrument was operated both contacting the slide under a load of 0.3 N and non-contacting at various distances from the slide surface. This was repeated with the tip parallel to the slide. The area of medium removed was quantified by digital image analysis. RESULTS: It was found that AMS removed the plaque substitute from around the tip. The TFI-9 insert significantly removed more material with increasing displacement amplitude (P <0.05). Significantly larger areas of plaque substitute were removed when the tips of the TFI-3, TFI-9, and P-12 inserts were orientated perpendicularly to the slide compared to the parallel orientation (P <0.05). Of the 4 inserts used, the TFI-9 insert removed the most material while the straight tip produced no apparent removal. Removal by AMS required the presence of a water medium and such forces were found to decrease with distance from the scaling tip. No plaque substitute removal was seen at a distance of 7 mm for the TFI-9 insert at 37.5 microm displacement with the tip orientation parallel to the slide. CONCLUSIONS: It is concluded that AMS occurs around ultrasonic scalers and this depends on the displacement amplitude, tip orientation, and presence of a water medium. AMS may play a role in disruption of subgingival biofilms associated with periodontal disease.

Acoustics↗
PubMed2004

The comparative effect of ultrasonic scalers on titanium surfaces: an in vitro study.

BACKGROUND: Professional maintenance is as important for patients with dental implants as it is for patients with natural teeth. However, no proper maintenance instruments have been available for implant patients. The purpose of this in vitro study was to compare the effects of a new ultrasonic scaler (VR), a conventional ultrasonic scaler (SP), and a plastic scaler (PS) on titanium surfaces. METHODS: To simulate subgingival conditions, the implant healing abutments were connected to acrylic resin blocks with artificial gingiva using silicon impression material. The abutments were painted with ink as an artificial form of debris. The ink was removed with the VR, SP, or PS scaler for 60 seconds under standardized conditions, and the removal rate was calculated. The roughness of the abutment surface was measured with a profilometer and observed by scanning electron microscopy (SEM). RESULTS: The removal rate using the VR and SP scalers was higher than that using the PS scaler. No significant differences in the surface roughness or SEM observations were found among the VR, SP, or PS scalers. CONCLUSIONS: In this preliminary study, the new ultrasonic scaler and conventional ultrasonic scaler were shown to be useful for removing artificial debris and produced no significant damage to titanium surfaces compared to plastic scalers. We concluded that new and conventional ultrasonic scalers with a non-metal tip would be suitable for implant maintenance.

Acrylic Resins↗
PubMed1996

Comparison of a respiratory suspension aerosolized by an air-jet and an ultrasonic nebulizer.

In the absence of USP standards and performance monographs, this research sought to determine if differences in the aerosolization mechanism (air-jet vs. ultrasonic) affected droplet and insoluble particle deposition of a nebulized model respiratory suspension. Five milliliters of a model suspension containing 0.1% w/v fluorescein (to estimate droplet deposition) and known quantities of 1, 3, and 6 microns latex spheres (representing insoluble drug particles) was aerosolized from an air-jet and an ultrasonic nebulizer. Nebulized output was collected in a modified Andersen impactor. Samples were analyzed spectrophotometrically (490.5 nm) and by a Coulter Counter to estimate droplet and sphere deposition, respectively. The distribution of droplets throughout the modified impactor for both nebulizers suggested that both the air-jet and the ultrasonic nebulizer produced droplets (0.4 to 10 microns in aerodynamic diameter) large enough to incorporate 1, 3, and 6 microns insoluble spheres. However, Coulter Counter analysis of the sphere distribution revealed that while the air-jet nebulized output contained spheres of all sizes, this was not true for the ultrasonic nebulizer. In the ultrasonic nebulizer, 99% of the spheres (irrespective of size) were not aerosolized and were recovered from the nebulizer reservoir at the aerosolization end point. The results highlight the importance of evaluating performance of a respiratory suspension in combination with a specific nebulizer. When conducting in vitro inertial deposition testing of a respiratory suspension, it is inappropriate to assume that deposition trends of droplets will predict the deposition of the insoluble dispersed phase.

Aerosols↗
PubMed2002

Ultrasonic aspiration hepatectomy for 136 patients with hepatocellular carcinoma.

AIM: To study the operative injury, post-operative complications, the hospitalization time, the post-operative survival rate of ultrasonic aspiration hepatectomy with a domestic new type of ultrasonic surgical device in comparison with that of conventional techniques of hepatectomy. METHODS: A total 136 patients with hepatocellular carcinoma (HCC, including 12 patients in 1991 and 124 consecutive patients from July 1995 to December 2000) underwent ultrasonic aspiration in liver resection (group T) and 179 HCC patients received conventional hepatectomy during the corresponding period (group C). The results of the two groups were compared statistically. RESULTS: There was no significant difference in the mean operation time between group T (152+/-11 min) and C (144+/-11 min). No operation or hospital death occurred in both groups. In group T, the mean volumes of bleeding (463+/-15 ml) and blood transfusion (381+/-12 ml) were markedly less than those in group C (557+/-20 ml, and 507+/-18 ml, respectively, P<0.05). The mean hospitalization time of group T (8.9+/-0.6 d) was markedly shorter than that of group C (11.7d+/-0.6 d) (P<0.05). The incidence of complications in group T was markedly lower than in group C, post-operative jaundice occurred in 4/136 and 31/179, respectively (P<0.05), liver failure in 0/136 and 2/179, cholorrhea in 0/136 and 6/179, hydrothorax in 21/136 and 39/179 (P<0.05), ascices in 9/136 and 54/179, respectively (P<0.05 ). There was no significant difference in the 1-year survival rate between the two groups (P>0.05), while the 3-year survival rate of group T (64.2 % ) increased markedly as compared with that of group C (55.7 %) (P<0.01). CONCLUSION: The ultrasonic aspiration hepatectomy with a domestic new type of ultrasonic surgical device could evidently reduce the operative injury and post-operative complications, shorten the hospitalization time and prolong the survivals of HCC patients.

Adolescent↗