Use of intraoperative ultrasonography during hepatic transplantation

The aim of this study was to evaluate if intraoperative vascular ultrasonography is of clinical value in the perioperative management of hepatic transplant patients. Fifteen intraoperative ultrasonographic examinations were performed on 13 patients (five female, eight male) during transplantation. These patients had clinically suspected vascular compromise. Among the 13 patients studied intraoperatively, five were correctly diagnosed as having hemodynamically significant vascular compromise. Of the intraoperative vascular sonographic examinations, the results of 13 were in concordance with the surgical impression as to whether further intervention was necessary or if the procedure could be terminated. Intraoperative sonography demonstrates potential to be of aid to the surgeon in recognition of vascular compromise.     

Use of intraoperative laparoscopic sonography in the diagnosis of hepato-pancreatic-duodenal duct diseases

Laparoscopic doppler sonography was conducted in 245 patients. Its application have permitted to diagnose the diseases of gallbladder, pancreas, liver, common bile duct, duodenum, to determine the inflammation form, to substantiate the extent and tactics of surgical intervention and to reduce the complications frequency.     

Research in neurosurgery

We have measured the levels of glucose and sugar alcohols in the lens epithelium of 24 non-diabetic and 21 diabetic patients undergoing extracapsular cataract extraction for age-related cataract. Lens status was assessed preoperatively according to the Lens Opacities Classification System II. In comparison to non-diabetics, the lens epithelia of diabetic patients have increased levels of glucose and sorbitol, and lower content of myo-inositol. Both myo-inositol decrease and sorbitol accumulation are strictly related to the fasting blood sugar level. No correlation or trend was detected in diabetic subjects between myo-inositol or sorbitol level and cataract type. In non-diabetic patients nuclear opacification was associated with a significant increase of myo-inositol level in lens epithelium.     

Use of colour and spectral Doppler ultrasound examination in gynaecology

Objective: To review and sum up the published literature on gynecological Doppler ultrasound examination. Methods: Publications on gynecological Doppler ultrasound examination already known by the author, publications found in the bibliographic database Medline, and publications found in the reference lists of available studies were read, and relevant information was extracted and summarized. Results: Reference data representative of normal findings at transvaginal color and spectral Doppler ultrasound examination of the uterine and ovarian arteries have been established in healthy pre- and post-menopausal women and in normal early pregnancies. Blood flow velocities in the uterine and ovarian arteries change during the normal menstrual cycle and are very different in pre- and post-menopausal women. Lower blood flow velocities and higher pulsatility index (PI) values have been recorded in the ovarian arteries after the menopause. Uterine artery blood flow velocities increase and uterine artery PI values and resistance index (RI) values decrease with gestational age in the first trimester. There is not yet an established role of the gynecological Doppler ultrasound examination in clinical practice. It remains unclear whether the gynecological Doppler ultrasound examination contributes substantially to the clinical management of early pregnancy complications or infertility problems, to the differential diagnosis of pelvic masses or uterine pathology. Conclusions: Large prospective studies-preferably randomized controled trials-are needed to determine the clinical value of the gynecological Doppler ultrasound examination. Copyright 1997 Elsevier Science Ireland Ltd.     

Use of ultrasound in spinal arthrodesis. A rabbit model

STUDY DESIGN: The biomechanical and histologic characteristics of posterolateral spinal fusion in a rabbit model with and without the application of low-intensity ultrasound were analyzed. OBJECTIVES: To evaluate the use of ultrasound to improve the spinal fusion rate and biomechanical characteristics of the fusion mass in a rabbit model. SUMMARY OF BACKGROUND DATA: This is the first study in which the benefits of ultrasound in spinal fusion have been assessed. Posterolateral intertransverse process fusion in the rabbit has a pseudarthrosis rate similar to that recorded in humans (5-40%). METHODS: Fourteen New Zealand White rabbits were randomly assigned to each of two groups to undergo spinal fusion using autologous bone with ultrasound or autologous bone without ultrasound. A specially designed plastic constraint was used to focus the ultrasound over the rabbits' lumbar spine 20 minutes per day. Animals were killed at 6 weeks for biomechanical and histologic testing. RESULTS: The rate of pseudarthrosis, evaluated radiographically and manually in a blinded fashion, decreased at a statistically significant rate (from 35% to 7%) with ultrasound. Biomechanical analysis of the fusion mass showed that ultrasound resulted in statistically significant increases in stiffness (33%; P = 0.03), area under the load displacement curve (25%; P = 0.05), and load to failure of the fusion mass (24%; P = 0.04). Qualitative histologic assessment showed increased bone formation in those fusions exposed to ultrasound. CONCLUSIONS: Lumbar spinal fusion is a complex biologic process. The results of the current study demonstrate the reproducibility of a rabbit fusion model and the ability of ultrasound to induce a statistically significant increase in fusion rate, stiffness, area under the load displacement curve, and load to failure of the fusion mass. These results provide a basis for continued evaluation of biologic improvement of spinal arthrodesis with the use of ultrasound.     

New techniques in neurosurgery

Society demands for exactness and low complication rates of surgical treatment are high. Surgical training in the apprentice manner has been significantly reduced in Denmark since 1981 and e.g. the ability to visualize in three dimensions among younger neurosurgeons has diminished. Computer technology now makes it possible to create 3-D images that with incorporation of functionality leads to a faster and better understanding of neuroanatomy. In addition--for the sake of precision--true robotic instrumentation and navigational instruments have been introduced. The technological investments are compensated by reduced costs due to operative complications. A prerequisite for these developments are a close collaboration between medical doctors and engineers, keeping the respect for humanity intact. A survey of developmental areas in the neurosurgical techniques of today is given.     

Technical adjuncts in neurosurgery

Modifications of several surgical adjuncts are presented: a balanced microscope stand with mouthpiece and hand controls, a piston release operating stool, a support device for resting the surgeon's arms, a table mounted arm with coupling head for attaching self-retaining brain retractors, fish hook retractors, suction tubes, bipolar forceps, aneurysm clips and mobile tip mirrors. Although many of these changes are minor, they considerably facilitate microneurosurgical procedures.     

Laser-Doppler flowmetry in neurosurgery

It is theorized that persons with strong sense of coherence are likely to define an event as less stressful and be able to manage a problem more successfully than those with weak sense of coherence. The study investigated the relationship among coherence and personal and environmental concerns, appraisal of threat, emotional distress, and high-risk behaviors in minority women at risk for human immunodeficiency (HIV) infection. As predicted, a significant negative relationship was seen between level of coherence and concerns. Moreover, women strong in coherence reported less negative appraisals of threat, less emotional distress, and fewer high-risk behaviors than those with weak coherence. Results of tests of a path model investigating the impact of coherence and appraisal on distress and risk revealed coherence to be significantly and negatively associated with appraisal, distress, and risk, both directly and indirectly through its association with appraisal. The path model accounted for 45% of the variance in distress, 10% of the variance in appraisal, and 4% of risk behavior. Continuing investigation of factors such as coherence that can lessen the seriousness of environmental stressors is imperative as it relates to women at risk for HIV infection.     

Use of a rapid intraoperative parathyroid hormone assay in the surgical management of parathyroid disease

We present recent developments in the area of glycosaminoglycans (GAGs) and their possible interaction with insulin-like growth factor-I (IGF-I). GAGs are constituents of proteoglycans, and the combination of a core protein and a specific GAG makes a unique proteoglycan with a precise developmental pattern and with the ability to bind growth factors. This process is apparently regulated by the moiety of the peripheral GAGs. The supplementation of GAGs promotes neuritogenesis in vitro and stimulates nerve regrowth and muscle reinnervation, an effect correlated with an increase in trophic factor mRNA expression. In the case of neonatal nerve lesion, there is in addition an enhanced motor neuron survival, accompanied by higher levels of IGF-I in plasma and denervated muscle. The neurotrophic and neuroregenerative effects of exogenous GAGs were also observed in motor neuron disease in the wobbler mouse.     

What''s new in pediatric neurosurgery

During the past year, there have been some significant papers dealing with pediatric neurosurgical problems. These papers deal with arteriovenous malformations, spinal cord injury, brain tumors and hydrocephalus. The papers are summarized in the following review.     

Use of ultrasound for diagnosis of foreign bodies of the brain

With the aid of modern ultrasonic diagnostic devices experiments were conducted in order to receive signals from foreign bodies of a different composition, non-radiocontrast ones including. Experiments on 10 human brain preparations revealed the typical peculiarities of echo-signal from foreign bodies in the cerebral matter. In 30 adult mongrel dogs it was proved that foreign bodies can be diagnosed in the course of primary and secondary debridement of skull and brain wounds. It was found that the shape and size of the foreign bodies in the human brain can be most explicitly determined with the aid of a specially designed device having a high azimuthal resolution.     

Use of ultrasound methods in vascular and circulatory diseases (author's transl)

The paper summarizes the principles, techniques and efficiency of ultrasound methods as indicator systems in the assessment of the peripheral and cerebral arteries; our studies predominantly refer to the use of these simple, non-invasive procedures in combination with sphygmo-oscillography and dynamographic circulation analysis, respectively. Ultrasound Doppler flowmetry (Pulse Doppler method), which permits relative measurements of the flow velocity in the peripheral haemodynamic regions, is of great importance in the rapid ascertainment of the patency of the major arterial trunks and the non-palpable vessels and also in the diagnosis, localization and follow-up control of stenoses and occlusions. Changes in the flow velocity due to organic or functional factors can be recorded by this method acoustically, oscilloscopically and graphically; measurements of the systolic blood pressure in the limb arteries by the Doppler technique provide semi-quantitative information in regard to the condition of the circulation. The registration of Doppler signals over the supra-orbital artery before and after compression of the superficial temporal artery and the common carotid artery has become established as a screening procedure for stenoses of the internal carotid artery. Ultrasound echography, which enables pulse registration and determination of vessel diameters, especially of the carotid siphon, can also be used for the detection of obstructions in the region of the internal carotid artery, as well as the vertebral artery.     

Local use of levomycetin in neurosurgery]

A method of local application of the unsoluble medicinal form of chloramphenicol during operations has been developed. Administration of the preparation in a dose up to 2g under an osteal or cutaneous graft induces no side complications and forms a depot of the agent therapeutic concentrations for more than 8 days. There exists a direct relationship between the increasing of staphylococcus resistance to chloramphenicol and the quantity of the agent used in patients.     

Dural tenting sutures in pediatric neurosurgery

Dural tenting sutures were used on a selective basis in 329 consecutive cranial operations in children; 16 (4.8%) required dural tenting sutures for the control of epidural bleeding and 313 (95.2%) required no dural sutures. Dural tenting sutures were never placed for prophylaxis or to satisfy a routine. Reoperation for postoperative epidural hematoma was required in 1 child (0.3%) and that child was subsequently discovered to have hemophilia. The author concludes that there is no compelling evidence for the prophylactic use of dural tenting sutures in children.