Nonnegligent foreign object cases.
Explore the source record for details and available documents.
Emergencies↗
SEARCH · Search PubMed
Results for “Surgical Instruments”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Robotic radiosurgery with noncylindrical collimators.
In radiosurgery, a moving beam of radiation acts as an ablative surgical instrument. Conventional systems for radiosurgery use a cylindrical radiation beam of fixed cross section. The radiation source can be moved only along simple, standardized paths. A new radiosurgical system based on a six-degree-of-freedom robotic arm has been developed to overcome limitations of conventional systems. We address the following question: Can dose distributions generated by robotic radiosurgery be improved by using noncylindrical radiation beams? This includes static noncylindrical collimators and collimators of adaptable cross section. Geometric methods for planning the shape of the beam in addition to planning beam motion are developed. Design criteria considered in this context are treatment time, radiation penumbra, and transparency of interactive treatment planning. An experimental evaluation compares distributions generated with our new radiosurgical system using cylindrical beams to distributions generated with beams of adaptable, noncylindrical shapes.
Computer Simulation↗
Catching up.
The medical school I (S.M.) attended did not require dissection of a cadaver to fulfill the requirements of the anatomy curriculum. I had "learned" human anatomy through lectures, text books, and an atlas, but did no dissection. Although it was difficult doing anatomy that way, I passed basic science exams with high marks and did well on the board exams (NBME). I graduated from medical school with distinction and thought I was well prepared for residency. To my surprise, dissection of the orbit and periorbital regions and cranial cavity were included in my ophthalmology residency and were to pose a challenge for me. I requested the aid of a medical school anatomist to help me face this challenge. Not only did I learn the art of dissection, I gained considerable knowledge in anatomy (much of it clinically relevant), acquired better skill with surgical instruments and enhanced my logical and critical thinking ability. This viewpoint is based upon a diary I kept during my dissection experience.
Anatomy↗
Usefulness of microsurgery in the training of the general surgeon.
It is a common opinion that general surgery is the first step for whoever approaches a surgical discipline, and that whoever practices training in general surgery should learn the rudiments of each surgical branch. The role of microsurgery in the training of the general surgeon has not been well-established. Clinical applications of microsurgery in general surgery are few and are rarely required, and have been connected strictly to restricted indications. However, we think that microsurgery could be very useful to the general surgeon because it allows the execution of experimental research on rats, the only possibility permitted by law. In these studies the microsurgeon can perform many times and in a short time the same surgical operation, thus improving his skill, and easily getting familiarity with surgical instruments and sutures.
General Surgery↗
Computer-aided fixation of spinal implants.
Medical imaging provides an important basis for modern diagnosis as well as for preoperative planning of surgical procedures. However, information gained cannot be transferred directly into the operating room. Furthermore, the safety and accuracy of the surgical intervention would be improved by interactive navigation of surgical instruments. These features are provided by the system for computer-aided fixation of spinal implants described in this paper.
Computer Simulation↗
A controlled trial to evaluate and compare a sutureless skin closure technique (Op-Site skin closure) with conventional skin suturing and clipping in abdominal surgery.
Sutureless wound closure employing a new product, Op-Site Skin Closure, was evaluated in comparison with two standard techniques of skin closure, using interrupted nylon sutures and Michel clips. The trial involved 110 patients undergoing elective and emergency abdominal surgery. The results showed that Op-Site Skin Closure was as good as the conventional techniques of skin closure with the advantages that it is easier and quicker to apply, produces a superior cosmetic result and, consequently, has gained excellent patient and nurse acceptance.
Abdomen↗
A double clamp for tantalum clips in parietal cell vagotomy.
Explore the source record for details and available documents.
Humans↗
Wound infection after abdominal incision with scalpel or diathermy.
Explore the source record for details and available documents.
Abdominal Muscles↗
New needle to simplify removal of impalpable breast tumours.
Explore the source record for details and available documents.
Breast↗
Non-suture methods of vascular anastomosis.
BACKGROUND: The main aim of performing a vascular anastomosis is to achieve maximal patency rates. An important factor to achieve that goal is to minimize damage to the vessel walls. Sutures inevitably induce vascular wall damage, which influences the healing of the anastomosis. Over time, several alternatives to sutures have become available. METHODS: A Medline literature search was performed to locate English, German and French language articles pertinent to non-suture methods of vascular anastomosis. Manual cross-referencing was also performed and many historical articles were included. RESULTS AND CONCLUSION: The non-suture techniques can be categorized into five groups based on the materials used: rings, clips, adhesives, stents and laser welding. With all these techniques a faster and less traumatic anastomosis can be made compared with sutures. However, each device is associated with technique-related complications. As a consequence, suturing continues to be the standard approach. The disadvantages of the non-suture techniques include: rigidity and a non-compliant anastomosis with rings; toxicity, leakage and aneurysm formation with adhesives; early occlusion with stents; cost, reduced strength in larger-sized vessels and demand for surgical skills with laser welding. Further refinement is needed before widespread adoption of these techniques can occur. Clips, however, may be particularly promising but long-term evaluation is required.
Anastomosis, Surgical↗
Randomized clinical trial of the effects of abdominal drainage after elective hepatectomy using the crushing clamp method.
BACKGROUND: Abdominal drainage is a standard procedure after hepatectomy, but this practice has been challenged recently. METHODS: Between September 2004 and March 2005, 120 consecutive patients who had undergone hepatic resection by the same surgical team were randomly allocated into drainage and no drainage groups (60 in each group). Patient characteristics, preoperative liver function, presence of cirrhosis, resection-related factors and postoperative complications were compared between the two groups. RESULTS: The groups were comparable in terms of demographics, indications for surgery, preoperative liver function test results, presence of cirrhosis, extent of hepatectomy, intraoperative blood loss and requirement for blood transfusion. Symptomatic subphrenic collection and pleural effusion occurred in four patients (7 per cent) who had abdominal drainage and three (5 per cent) who did not. Local wound complications occurred in 17 (28 per cent) and two (3 per cent) patients respectively (P < 0.001). The postoperative hospital stay was similar in the two groups. Multivariate analysis indicated that the presence of cirrhosis and abdominal drainage were independently related to the development of postoperative wound complications. CONCLUSION: Routine abdominal drainage is unnecessary after elective hepatectomy using the crushing clamp method.
Blood Loss, Surgical↗
Titanium-cell interaction: analysis of gene expression profiling.
Titanium and its alloys are used worldwide in surgery. Dental implants, screws and plates, prostheses, and surgical instruments are made with titanium-based metals. The favorable characteristics that make this material desirable for implantation are (a) mechanical proprieties and (b) biocompatibility. The latter has been demonstrated by in vivo studies with animal models and clinical trials over a 40-year period. However, the exact effect of titanium on cells is still not well characterized. Expression profiling by DNA microarray is a new molecular technology that allows the analysis of gene expression in a cell system. Several genes whose expression was significantly up- or downregulated in an osteoblast-like cell line (MG-63) on titanium were identified with the use of DNA microarrays containing 19,200 genes. The differentially expressed genes are associated with a broad range of functional activities, including apoptosis, vesicular transport, and structural function. It was also possible to detect some genes whose function is unknown. The data reported are, to the author's knowledge, the first genetic portrait of titanium-cell interaction. They may help to provide a better understanding of the molecular mechanisms of titanium biocompatibility and serve as a model for studying the biocompatibility of other materials.
Animals↗
Comparison of wound healing between chopped mode-superpulse mode CO2 laser and steel knife incision.
The healing of surgical incisions made with the steel knife and CO2 laser chopped wave mode (ChW) or rapid superpulse (RSP) mode were compared using histologic parameters and breaking strength of the scars on postoperative day 14. Using a miniature pig model the Sharplan 1100 laser incisions were made with an average power of 15 W and power density of 7.68 kW/cm2. Histological sections on postoperative day 14 revealed the knife scar measured .49 mm, was hypocellular, and contained visible bundles of collagen fibers. Both CO2 laser scars were less mature, the ChW scar measured 1.04 mm, the RSP scar measured 1.37 mm, and both contained cellular granulation tissue without visible collagen fibers. The breaking strength of the scars was measured with a tensiometer. Laser wounds were weaker than the knife wound. Scheffe test for variables was significant at P = .01 between the two laser modes and the knife. No significant difference was noted in the breaking strengths of incisions made with the chopped mode and superpulse mode.
Animals↗
Prevalence of lymphoreticular prion protein accumulation in UK tissue samples.
This study aims to provide an estimate of the number of individuals in the UK who may be incubating variant Creutzfeldt-Jakob disease and at risk of causing iatrogenic spread of the disease. Lymphoreticular accumulation of prion protein is a consistent feature of variant Creutzfeldt-Jakob at autopsy and has also been demonstrated in the pre-clinical phase. Immunohistochemical accumulation of prion protein in the lymphoreticular system remains the only technique that has been shown to predict neurological disease reliably in animal prion disorders. In this study, immunohistochemistry was used to demonstrate the presence of prion protein, with monoclonal antibodies KG9 and 3F4, in surgically removed tonsillectomy and appendicectomy specimens. The samples were collected from histopathology departments across the UK and anonymised prior to testing. Samples were tested from 16 703 patients (14 964 appendectomies, 1739 tonsillectomies), approximately 60% of whom were from the age group 20-29 years at operation. Twenty-five per cent of the samples were excluded from the final analyses because they contained inadequate amounts of lymphoid tissue. Three appendicectomy samples showed lymphoreticular accumulation of prion protein, giving an estimated prevalence of 3/12 674 or 237 per million (95% CI 49-692 per million). The pattern of lymphoreticular accumulation in two of these samples was dissimilar from that seen in known cases of variant Creutzfeldt-Jakob disease. Although it is uncertain whether immunohistochemical accumulation of prion protein in the lymphoreticular system is specific for variant Creutzfeldt-Jakob disease, it has not been described in any other disease, including other forms of human prion disease or a range of inflammatory and infective conditions. These findings reinforce the importance of measures taken by the UK Department of Health to reduce the risk of spread of variant Creutzfeldt-Jakob via blood products and surgical instruments, and of the urgency to proceed with large-scale screening of fresh tonsil specimens for the presence of prion protein.
Adolescent↗
Effect of manual hyperinflation on haemodynamics in an animal model.
BACKGROUND AND PURPOSE: Manual hyperinflation is a physiotherapy technique that improves static compliance and mobilizes secretions, but has the potential to alter haemodynamic function. The aim of the present study was to investigate the effects of manual hyperinflation on haemodynamic function in a healthy animal model, without the usual confounding effects inherent in an heterogeneous intensive care population. METHOD: The study used a within-subjects design, in an animal research theatre. Nine healthy sheep (eight Border Leicester, one Merino, mean weight 39.5 kg, standard deviation (SD) 1.6 kg) completed the study. The sheep were induced (thiopentane 15-20 ml), intubated, ventilated and surgically instrumented for an arterial line and pulmonary artery catheter. Anaesthesia was maintained by 1.5% halothane/oxygen. Manual hyperinflation was delivered for two minutes with a Mapleson C circuit, using a peak inspiratory pressure of 35 cmH2O and an inspiratory:expiratory ratio of 2:1. RESULTS: Mean tidal volume during manual hyperinflation was 294% (SD 22%) of the ventilator tidal volume. A paired Student's t-test demonstrated that cardiac output (thermodilution method) decreased significantly (p < 0.05) and systemic vascular resistance increased significantly (p < 0.01) after manual hyperinflation. A repeated-measures analysis of variance (ANOVA) and a least-significant difference pairwise comparison revealed that mean arterial pressure and pulse pressure decreased significantly during (p < 0.01) and increased significantly (mean arterial pressure, p < 0.05 and mean pulse pressure p < 0.001) after the technique. Pulmonary artery pressure also increased significantly during manual hyperinflation (p < 0.01). There were no significant effects on right atrial pressure, pulmonary artery occlusion pressure or heart rate. CONCLUSION: Significant haemodynamic changes occurred in this animal model. The increased intrathoracic pressure, applied for an increased period during inspiration, decreased cardiac output with compensatory vasoconstriction evident by the increased systemic vascular resistance and mean arterial pressure. The results suggest that there may be a decrease in cardiac output after increased positive pressure in subjects with normal cardiac and respiratory function.
Animals↗
Cadaver validation of intensity-based ultrasound to CT registration.
A method is presented for the registration of tracked B-mode ultrasound images to a CT volume of a femur or pelvis. This registration can allow tracked surgical instruments to be aligned with the CT image or an associated preoperative plan. Our method requires no manual segmentation of either the ultrasound images or the CT volume. The CT and US images are processed to produce images where the image intensity represents the probability of the presence of a bone edge. These images are then registered together using normalised cross-correlation as a similarity measure. The parameter which represents the speed of sound through tissue has also been included in the registration optimisation process. Experiments have been carried out on six cadaveric femurs and three cadaveric pelves. Registration results were compared with a "gold standard" registration acquired using bone implanted fiducial markers. Results show the registration method to be accurate, on average, to 1.7 mm root-mean-square target registration error.
Algorithms↗
Neuropathology and molecular biology of variant Creutzfeldt-Jakob disease.
The neuropathological features of human prion diseases are spongiform change, neuronal loss, astrocytic proliferation and the accumulation of PrP(Sc), the abnormal isoform of prion protein (PrP). The pattern of brain involvement is remarkably variable and is substantially influenced by the host PrP genotype and PrP(Sc) isotype. Variant Creutzfeldt-Jakob disease (vCJD) is a novel human prion disease which results from exposure to the bovine spongiform encephalopathy (BSE) agent. The neuropathology of vCJD shows consistent characteristics, with abundant florid and cluster plaques in the cerebrum and cerebellum, and widespread accumulation of PrP(res) on immunocytochemistry. These features are distinct from all other types of human prion disease. Spongiform change is most marked in the basal ganglia, while the thalamus exhibits severe neuronal loss and gliosis in the posterior nuclei. These areas of thalamic pathology correlate with the areas of high signal seen in the thalamus on magnetic resonance imaging (MRI) examination of the brain. Western blot analysis of PrP(Sc) in the brain in vCJD tissue shows a uniform isotype, with a glycoform ratio characterized by predominance of the diglycosylated band, distinct from sporadic CJD. PrP(Sc) accumulation in vCJD is readily detectable outside the brain, in contrast with other forms of human prion disease, particularly in the lymphoid system and in parts of the peripheral nervous system. This has raised concern about the possible iatrogenic transmission of vCJD by contaminated surgical instruments, or blood. All cases of vCJD are methionine homozygotes at codon 129 of the prion protein gene (PRNP). Continued surveillance is required to investigate cases of vCJD in the UK and other countries where BSE has been reported, particularly as cases of 'human BSE' in individuals who are MV or VV at codon 129 of the PrP gene have not yet been identified. Histological, genetic and biochemical techniques are essential tools for the adequate diagnosis and investigation of human prion diseases.
Brain↗
Maturational topography of the visual evoked potential in fetal lambs.
The normal maturational course of the visual evoked potential (VEP) in human newborns and infants is well documented. Unfortunately, there is a paucity of data about VEP maturation in the 'normal' preterm infant. Since this population is at risk to develop many abnormalities affecting the VEP (intraventricular hemorrhage, hydrocephalus, and retinopathy of prematurity), one must question whether such VEP data collected from this group is representative of normal maturation. To provide normative parametric developmental data we have been studying VEP development in fetal lambs. Six fetal lambs between 105 and 120 days gestational age were externalized and surgically instrumented with subcutaneous recording electrodes placed over the occipital and parietal regions. High-intensity light-emitting diodes (LEDs) externalized fiberoptic cables were secured adjacent to the orbit. from 108 to 141 days gestation, fetal VEPs were recorded in response to bright flash stimulation and the maturational topography was investigated. Over the occipital regions, the emergence of major positivities at P400 and P650 were observed beginning around 120 days gestation. Over the parietal area, the emergence of P200 and P500 components was observed by 128 days gestation. The latency-maturation functions revealed that the slope of the parietal function was steeper than the occipital counterpart, suggesting that the maturation of parietal neurons occurs at a faster rate than neuronal development in the occipital regions.
Animals↗