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At least 775 records · Page 43Linked to original sources
PubMed1999

Endoscopic axillary exploration and sentinel lymphadenectomy.

BACKGROUND: Minimally invasive approaches have changed the practice of surgery in several specialties. The purpose of this study was to develop a reproducible endoscopic technique for the evaluation of the axilla in breast cancer patients. METHODS: A total of 23 patients with biopsy-proven breast carcinoma were enrolled. Patients were positioned in the supine position with the ipsilateral arm abducted at 90 degrees. A 1-cm skin incision was made at the superior aspect of the axilla. Dissection was carried bluntly to the lateral border of the pectoralis major. A balloon distention device was inserted into the tract and distended under endoscopic vision to create a working space. Insufflation was initiated up to a pressure of 8 mmHg. A 30 degrees laparoscope was introduced for visualization of axillary contents. One or two additional 5-mm cannulas were placed as needed under direct visualization. Manipulation of axillary contents was performed, and in 19 patients a sentinel node identification technique was applied. RESULTS: In all patients, using insufflation and minimal instrument dissection, the axillary vein, long thoracic, and thoracodorsal nerves were found in their usual anatomical locations. Utilizing blunt and sharp dissection, the axilla was thoroughly inspected, and individual lymph nodes were easily identified and extracted. In 11 of 19 patients, a sentinel node or blue dye was identified using isosulfan blue. There was a procedure concordance of 84%, and there were no complications. CONCLUSIONS: We describe a novel endoscopic technique for the evaluation of the axilla in breast cancer patients. This technique allows (a) creation of a minimally invasive working space within the axilla, (b) recognition of key axillary anatomic landmarks, and (c) instrument manipulation within the axilla to identify and extract lymph nodes, and apply the sentinel node technique. This is the first report of a minimally invasive approach to axillary exploration to employ sentinel lymph node mapping.

Axilla↗
PubMed2002

The effect of the Relton-Hall operative frame on trunk deformity in adolescent idiopathic scoliosis.

The prone operative position affects the geometry of the scoliotic spine. However, the literature provides little information concerning the effect of operative position on the scoliotic trunk geometry. This study compared the trunk deformity of 31 adolescent idiopathic scoliosis patients in two standardized positions: standing and prone on a Relton-Hall frame. The geometry of the trunk was assessed using 11 magnetic sensors placed on anatomical landmarks. Eight geometric indices of the trunk were compared using paired Student t-tests (alpha=0.01). The transverse rotation of shoulders, the coronal rotation of shoulders, the lateral shift of C7 with respect to S1, and the thoracic and lumbar angles of trunk rotation assessed in the operative position did not show any significant change compared to the standing position. Therefore, operative positioning using the Relton-Hall frame did not lead to an overall reduction in the scoliotic trunk deformity. Modifications to the Relton-Hall frame are required for optimal presurgical correction of the scoliotic trunk deformity.

Adolescent↗
PubMed2005

Validation of new clinical quantitative analysis software applicable in spine orthopaedic studies.

The objective of this study was to evaluate an X-ray films analysis software, i.e. to estimate the reliability and validity of clinical measurements by means of this software. The authors first performed tests of precision and reproducibility of measures. The precision for dynamic modules was estimated at +/-2 degrees for the lumbar analysis and +/-3 degrees for the cervical one. Mean reproducibility coefficients calculated for postural modules are about 4 degrees for the angular parameters and 3 mm for the linear ones. We also evaluated clinical applicability of the software through its validity. Reference values calculated on a population of healthy subjects showed agreement with the literature. Then, when analysing postural X-ray films of severe scoliotic patients, we found that inter-observer reproducibility coefficients show a lower reliability of measurements; the main cause seems to be the low visibility of anatomic landmarks due to the quality of X-ray films and to the degree of deformity. This study allowed to better estimate the reliability and the usefulness of this tool, allowing for multicentric studies and exchanges.

Cervical Vertebrae↗
PubMed2006

Frameless stereotaxy in a transmandibular, circumglossal, retropharyngeal cervical decompression in a Klippel-Feil patient: technical note.

Frameless stereotaxy, while most commonly applied to intracranial surgery, has seen an increasing number of applications in spinal surgery. Its use in the spine has been described to a greater degree in posterior rather than anterior surgical approaches, presumably due to the relative paucity of anatomical landmarks appropriate for frameless stereotactic registration in the anterior spine. This technical note illustrates the previously undescribed, successful use of frameless stereotaxy to the transmandibular, circumglossal, retropharyngeal surgical approach in a patient with Klippel-Feil syndrome.

Adult↗
PubMed2006

Assessment of CAOS as a training model in spinal surgery: a randomised study.

The objectives of this study were (1) to quantify the benefit of computer assisted orthopaedic surgery (CAOS) pedicle screw insertion in a porcine cadaver model evaluated by dissection and computed tomography (CT); (2) to compare the effect on performance of four surgeons with no experience of CAOS, and varying experience of pedicle screw insertion; (3) to see if CT with extended windows was an acceptable method to evaluate the position of the pedicle screws in the porcine cadaver model, compared to dissection. This was a prospective, randomised, controlled and blinded porcine cadaver study. Twelve 6-month-old porcine (white skinned Landrace) lumbar spines were scanned pre-operatively by spiral CT, as required for the CAOS computer data set. Computer randomisation allocated the specimens to one of four surgeons, all new to CAOS but with different levels of experience in spinal surgery. The usual anatomical landmarks for the freehand technique were known to all four surgeons. Two pedicles at each vertebral level were randomly allocated between conventional free hand insertion and an electromagnetic image guided surgery (NAVITRAK) and 6.5 mm cancellous AO screws inserted. Post-operatively, spiral CT was blindly evaluated by an independent radiologist and the spine fellow to assess the accuracy of pedicle screw placement, by each method. The inter- and intra-observer reliability of CT was evaluated compared to dissection. The pedicle screw placement was assessed as perfect if within the pedicle along its central axis, or acceptable (within < 2 mm from perfect), and measured in millimetres from perfect thereafter. One hundred and sixty-six of 168 pedicles in 12 porcine spines were operated on. Complete data were present for 163 pedicles (81 CAOS, 82 freehand). In the CAOS group 84% of screws were deemed acceptable or perfect, compared to 75.6% with the freehand technique. Screw misplacement was significantly reduced using CAOS (P = 0.049). Seventy-nine percent of CAOS screws were ideally placed compared with 64% with a conventional freehand technique (P = 0.05). A logistic linear regression model showed that the miss placed pedicle screw rate was significantly reduced using CAOS (P = 0.047). CAOS benefited the least experienced surgeons most (the research registrars acceptable rate increased from 70 to 90% and the spine fellow from 76 to 86%). CAOS did not have a statistically significant effect on the experienced consultant spine surgeon increasing from 70 to 79% (P = 0.39). The experienced general orthopaedic surgeon did not benefit from CAOS (P = 0.5). CT compared to dissection showed an intra-observer reliability of 99.4% and inter-observer reliability of 92.6%. The conclusions of this study were as follows: (1) an increased number of pedicle screws were ideally placed using the CAOS electromagnetic guidance system compared to the conventional freehand technique; (2) junior surgeons benefited most from CAOS; (3) we believe CAOS (Navitrak) with porcine lumbar spines evaluated by post operative CT, represents a useful model for training junior surgeons in pedicle screw placement; (4) experienced spine surgeons, who have never used CAOS, may find CAOS less helpful than previously reported.

Animals↗
PubMed2005

Microsurgical considerations of the anterior spinal and the anterior-ventral spinal arteries.

BACKGROUND: There are few data describing the microanatomy of the anterior-ventral spinal (AVSA) and anterior spinal arteries (ASA) and discussing their clinical and surgical implications. We describe the anatomical features of this arterial complex, and highlight their use when planning and performing surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum. METHOD: The microsurgical anatomy and branching pattern of the AVSA and the ASA from fifty human cadaver brain stems is described using a surgical microscope. RESULTS: We found one anterior-ventral spinal artery at each side in 30 of the brain stems (60%). The ASA was a direct branch emerging from the left vertebral artery (VA) in 15 (30%), from the right VA in 4 (8%), and from the basilar artery (BA) in one brain stem (2%). The previously described as "typical pattern" of the junction of the AVS arteries from both sides, was observed only in 9 brain stems (18%). The anterior communicating spinal artery (ACoSA) was observed in 15 brain stems (30%). Also multiple ACoS arteries were described in one brain stem. Both, the AVSA and the ASA were observed to send long circumferential branches that supplied irrigation to the olive in 42 (84%) brain stems. CONCLUSIONS: This anatomical study gives important information for a better understanding of the clinical picture of ischemic lesions of the brain stem, such as the medial medullary syndrome, and highlights the remarkable role of the AVSA and ASA as anatomical landmarks during the surgical approaches to lesions involving the ventral aspect of the medulla and the foramen magnum.

Basilar Artery↗
PubMed2001

Intracranial image-guided neurosurgery: experience with a new electromagnetic navigation system.

BACKGROUND: The aim of image-guided neurosurgery is to accurately project computed tomography (CT) or magnetic resonance imaging (MRI) data into the operative field for defining anatomical landmarks, pathological structures and tumour margins. To achieve this end, different image-guided and computer-assisted, so-called "neuronavigation" systems have been developed in order to offer the neurosurgeon precise spatial information. METHOD: The present study reports on the experience gained with a prototype of the NEN-NeuroGuard neuronavigation system (Nicolet Biomedical, Madison, WI, USA). It utilises a pulsed DC electromagnetic field for determining the location in space of surgical instruments to which miniaturised sensors are attached. The system was evaluated in respect to its usefulness, ease of integration into standard neurosurgical procedures, reliability and accuracy. FINDINGS: The NEN-system was used with success in 24 intracranial procedures for lesions including both gliomas and cerebral metastases. It allowed real-time display of surgical manoeuvres on pre-operative CT or MR images without a stereotactic frame or a robotic arm. The mean registration error associated with MRI was 1.3 mm (RMS error) and 1.5 mm (RMS error) with CT-data. The average intra-operative target-localising error was 3.2 mm (+/- 1.5 mm SD). Thus, the equipment was of great help in planning and performing skin incisions and craniotomies as well as in reaching deep-seated lesions with a minimum of trauma. INTERPRETATION: The NEN-NeuroGuard system is a very user-friendly and reliable tool for image-guided neurosurgery. It does not have the limitations of a conventional stereotactic frame. Due to its electromagnetic technology it avoids the "line-of-sight" problem often met by optical navigation systems since its sensors remain active even when situated deep inside the skull or hidden, for example, by drapes or by the surgical microscope.

Adult↗
PubMed2005

Revision cervical spine surgery using transarticular or pedicle screws under a computer-assisted image-guidance system.

BACKGROUND: The exact insertion of a cervical screw is technically demanding, especially when normal anatomic landmarks have been obscured and are difficult to identify, such as in revision surgery. The purpose of this study was to evaluate the efficacy of an image-guidance system to aid placement of transarticular and pedicular screws for revision cervical spine surgery. METHODS: Ten patients with recurrent myelopathy, including seven with cerebral palsy, two with a giant cell tumor, and one with rheumatoid arthritis, underwent computer-aided reconstruction surgery. The authors used a frameless stereotactic image-guidance system with simultaneous fluoroscopy. Postoperative computed tomography was used to determine the accuracy of the screw placement. RESULTS: There were no neurovascular complications and no correction loss. All patients showed solid bony union. All four C1/2 transarticular screws were exactly placed inside the pedicles. Of 47 pedicular screws, 11 showed a slight breach of the cortex. When a reference arc could not be attached to the relevant vertebra, the rate of cortical perforation of screws was high (5/10; 50%) compared with the rate when a reference arc was attached to the relevant vertebra (6/37; 16%). CONCLUSION: Although more advanced technology is hopeful, a computer-assisted image-guidance system with simultaneous fluoroscopy is useful for aiding revision surgery to achieve rigid fixation and ensure safety.

Bone Screws↗
PubMed2003

Subjective image quality of digital panoramic radiographs displayed on monitor and printed on various hardcopy media.

The subjective image quality of panoramic radiographs shown on a diagnostic computer monitor were compared with professional direct thermal prints and with common inkjet prints on different paper qualities. Indirect digital panoramic radiographs were obtained from 15 patients. The images were printed with a direct thermal printer in their original format. Afterwards, these were loaded in an imaging software programme (Microsoft Photo Editor) and assessed both on computer monitor and inkjet prints on transparency, glossy, satin and regular paper. Five observers assessed subjective image quality for different regions and anatomical landmarks on a 5-point rating scale. Data were statistically analysed and inter- and intra-observer performances were calculated. Best image quality was obtained with direct thermal prints, followed in descending order by panoramic images viewed on the monitor, inkjet prints on transparencies, glossy paper, satin paper and finally regular paper. The differences were significant except for monitor images versus direct thermal prints, inkjet-transparencies and inkjet-glossy images and inkjet-satin versus inkjet-glossy images. The subjective image quality of indirect digital panoramic images is different for images shown on the computer monitor and for printed images depending on both the printer and paper type used.

Adolescent↗
PubMed1999

Transverse changes after surgical closure of complete cleft lip, alveolus and palate.

Surgery for patients with unilateral (UCLP) and bilateral (BCLP) complete cleft lip, alveolus and palate has a considerable influence upon craniofacial growth. With respect to this, the cleft team at Hannover Medical School has attempted to reduce necessary surgical interventions to labioplasty, palatoplasty and veloplasty. Still, the effects of these operations influence maxillary growth to an extent which requires orthodontic treatment in all patients. This study focuses upon the transverse alterations of the alveolar arch and the deciduous dentition after lip and palate surgery. Dental casts prior to any surgical intervention and after labioplasty and complete palaotoplasty of the hard and soft palate were measured for transverse changes by using anatomical landmarks. The results indicate a significant occurrence of anterior relative to posterior arch width loss for both UCLP and BCLP patients. Orthodontic treatment should be planned and performed with respect to these findings in order to support craniofacial growth and prevent maxillary dental arch deficiency.

Alveolar Process↗
PubMed2006

Treating recurrence after a totally extraperitoneal approach.

BACKGROUND: One of today's most highly regarded procedures for treating inguinal hernia is the totally extraperitoneal approach (TEP), but it can on occasion lead to recurrence. This is commonly managed with an open repair, a transabdominal preperitoneal procedure (TAPP), or another TEP. We report here on our years of experience with the latter. METHODS: The endeavor to a secondary TEP is much the same as to a primary one, but certain differences are encountered as the operation proceeds. For example, many anatomical landmarks found in a first TEP cannot be seen in a second. There can also be a diminished amount of working space, and this occasionally leads to an open conversion. RESULTS: From September 1991 to September 2005, we repaired 1,526 hernias in 1,156 male patients, using the TEP in every case. Of these, 21 were TEPs after a previous TEP. In 3 cases, the space could not be opened, and they were converted to the open Lichtenstein. One patient had peritoneal tears that led to conversion and another had conversion because of excessive bleeding. There were no complications, no bladder or bowel injuries, no transfusions, no preperitoneal hematomas, and no fatalities. All patients were discharged the same day. CONCLUSIONS: A secondary TEP, open repair, and TAPP are alternative solutions to the problem of recurrence after TEP. However, any TEP involves a very prolonged learning curve for general surgeons, since they must learn the anatomy as well as the procedure, both at the same time. This is doubly true for the TEP after a previous TEP.

Hernia, Inguinal↗
PubMed2003

Head and neck nodal station images: guidance for three-dimensional radiation therapy treatment planning.

When we use radiation to treat cancer patients, the irradiated volume usually encloses the detectable tumor and any metastatic areas that are thought to be at risk. Usually, in three-dimensional (3D) radiation therapy, we need to define the clinical target volume (CTV), which identifies the areas suspected of containing microscopic metastasis. We can use a set of computed tomographic (CT) images to define these suspected areas, which we relate to nodal station distributions. The traditional method uses special anatomic landmarks for such definition. This lymph node image guidance method uses a set of CT images to show the relevant nodal stations and find the correlation between the suspected areas and the lymphatic pathways. First, we used CT images from head and neck cancer patients. Then, we designed a program to delineate the regional lymphatic areas in order to distinguish the position of all the major lymph nodes in the head and neck region. These lymph nodes were then used to assist the oncologist in developing treatment references. Finally, we established a database management system to determine the relationships between different lesions and lymph nodes, as well as correlations, with metastatic pathways. Defining these relationships on the CT images provided oncologists specific information that could be used to define the CTV more precisely for 3D radiation therapy.

Head and Neck Neoplasms↗
PubMed2005

Oncologic PET/CT: current status and controversies.

The introduction of integrated PET/CT has dramatically increased the worldwide rate of growth for PET, predominantly for oncologic imaging with the glucose analog 18F-fluorodeoxyglucose (FDG). A rapidly expanding body of literature demonstrates that the use of FDG-PET/CT and the resultant ability to interpret coregistered and fused PET and CT images lead to improved observer confidence and improved diagnostic performance by comparison with PET alone, CT alone, and visually correlated PET and CT. The value of PET/CT is likely to be even greater with new PET radiopharmaceuticals under development, many of which produce PET images with even fewer anatomical landmarks than FDG images. PET/CT is also likely to lead to the resurrection of 18F-fluoride as a principal agent for radionuclide bone imaging. There are a number of controversies related to PET/CT, including minimum training and experience requirements for interpreting physicians and defining new models for technical and professional reimbursement.

Clinical Competence↗
PubMed2006

Functional imaging of neuroendocrine tumours with PET.

Several pathophysiological attributes of neuroendocrine tumours (NET) can be addressed by specific radiolabelled probes. This paper provides an overview on the different radiopharmaceuticals that have been developed for Positron Emission Tomography (PET) of neuroendocrine tumours. A review of the literature on 18F-fluordeoxyglucose (FDG), biogenic amine precursors, somatostatin analogues and hormone syntheses markers is presented. Due to the highly specific tracers that lack any clear anatomical landmarking the advantages of integrated PET/CT are obvious. Amine precursors should be employed in most gastroenteropancreatic NET, FDG should be preserved for more aggressive, less differentiated NETs. Somatostatin analogues are the most promising tracers, since they can improve dosimetry in cases in which radiopeptide therapies are planned. In conclusion, the individual diagnostic approach using PET or the integrated PET/CT should be tailored depending on the histological classification and the differentiation of the tumour.

Animals↗
PubMed2007

Ultrasound-guided peripheral nerve blockade.

Peripheral nerve blockade (PNB) for orthopedic surgery is usually performed without visual guidance, relying mainly on surface anatomic landmarks and electrical stimulation to localize nerves. Moreover, multiple trial and error attempts to place a needle can frustrate the operator, cause unwarranted pain to the patient, and waste valuable time in the operating room. Inaccurate needle placement and spread of local anesthetic account for most PNB failures, whereas "trial and error" needle manipulations for nerve localization can cause complications. The recent application of ultrasound (US) to PNB affords real-time imaging of the target nerve, needle, and surrounding vasculature, such that needle proximity to the nerve is ensured and vascular puncture avoided. This article reviews the advantages, principles, and techniques of US for the most common types of PNB.

Brachial Plexus↗
PubMed2004

Taking the side of transperitoneal access for surgery in upper urinary tract.

Laparoscopic surgery has become a preferred treatment option for the management of upper urinary tract pathology. Large series of complex urologic operations have been published, with favorable outcomes. Although the early experience with urologic laparoscopy consisted almost exclusively of transperitoneal procedures, some surgeons prefer the retroperitoneal approach. The debate of retroperitoneal versus transperitoneal laparoscopy for upper tract pathology is complex because comparative and randomized studies are lacking. In contrast to the retroperitoneal approach, transperitoneal laparoscopic procedures allow for a larger working space, adequate maneuverability, and the presence of familiar anatomic landmarks. This article highlights our experiences and approaches to major laparoscopic upper urinary tract surgery for benign and malignant conditions. A summary of the published literature as it pertains to the transperitoneal approach also is presented.

Humans↗
PubMed1986

Significance of precordial ST-segment depression in inferior acute myocardial infarction as determined by echocardiography.

Despite numerous studies, the significance of precordial ST-segment depression in inferior wall acute myocardial infarction (AMI) remains unclear. No clinical studies have used 2-dimensional (2-D) echocardiography to compare AMI location in patients with or without so-called reciprocal ST changes. Therefore, the clinical, electrocardiographic, echocardiographic and angiographic features of 22 patients with their first transmural inferior AMI were prospectively examined. During the first day of AMI an echocardiographic mapping of the area of necrosis was obtained using all conventional views and a ventricular segmentation related to anatomic landmarks. Patients were categorized according to the presence (group I, n = 13) or absence (group II, n = 9) of precordial ST-segment depression, defined as more than 1 mm, measured 80 ms after the J point in at least 2 of the leads V1 to V4. Basal posterolateral akinesia was observed in 11 of the 13 patients in group I and in no patient in group II (p less than 0.001). Posterior right ventricular free wall akinesia was more frequent in group II (p less than 0.02). There was no difference in the prevalence of significant left anterior descending artery (LAD) narrowing (group I, 4 patients; group II, 3 patients). Posterolateral involvement should be strongly considered in the presence of precordial ST-segment depression in association with transmural inferior AMI.

Adult↗
PubMed1980

Enamel loss due to orthodontic bonding with filled and unfilled resins using various clean-up techniques.

An in vitro study using steel reference markers in the enamel of 100 premolars was carried out in order to determine the enamel loss resulting from each step in the placement and removal of bonded orthodontic attachments. Measurements were made by means of the optical system of a profile projector for orientation and positioning and a micrometer for quantification. Accuracy to within +/- 1 micron was achieved. The 10.7 micron of enamel lost during initial prophylaxis with bristle brush was greater than the 5.0 micron lost when a rubber cup was used, and the difference was statistically significant. A 90-second etch with phosphoric acid resulted in a mean loss of 6.9 micron, with no significant difference between liquid and gel forms. It was possible to clean up the unfilled resin with hand instruments only; this resulted in a mean enamel loss of 7.7 micron. Rotary instruments, however, were required for cleaning up filled resin. Within this group, more enamel was lost when the high-speed 7902 bur (19.2 micron) and green rubber wheel (18.4 micron) were used than when the low-speed 7111 bur (11.3 micron) was used. Total enamel loss ranged from 26.1 to 31.8 micron for unfilled resin and from 29.5 to 41.2 micron for filled resin, depending on the instrument used for prophylaxis and debonding. Twenty-seven of the teeth showed evidence of a perikymata-like structure after as much as 29 micron of enamel had been removed, questioning the reliability of anatomic landmarks as reference points in the study of enamel loss.

Acid Etching, Dental↗