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PubMed1991

Laparoscopic common bile duct exploration.

Operative common bile duct exploration, performed in conjunction with cholecystectomy, has been considered the treatment of choice for choledocholithiasis in the presence of an intact gallbladder. With the advent of laparoscopic cholecystectomy, the management of common bile duct stones has been affected. More emphasis is being placed on endoscopic sphincterotomy and options other than operative common duct exploration. Because of this increasing demand, we have developed a new technique for laparoscopic common bile duct exploration performed in the same operative setting as laparoscopic cholecystectomy. A series of five patients who successfully underwent common bile duct exploration, flexible choledochoscopy with stone extraction, and T-tube drainage, all using laparoscopic technique, is reported. Mean postoperative length of hospital stay was 4.6 days. Outpatient T-tube cholangiography was performed in all cases and revealed normal ductal anatomy with no retained stones. Follow-up ranged from 6 weeks to 4 months, and all patients were asymptomatic and had normal liver function tests.

Adolescent↗

PubMed1991

Laparoscopic exploration of the common bile duct: experience in 16 selected patients.

The authors' initial experience with transcystic duct and direct laparoscopic approaches to the exploration of the common bile duct is reported. The technique requires standard laparoscopic equipment, specialized endoscopes, and instruments developed for urologic stone manipulations. After cholangiography confirmed the presence of common bile duct stones, common duct stone extraction was performed in 16 selected patients age 20-88 years. Stones ranged in size from 1 mm to 30 mm and they were unsuspected in 60% of the patients. Five patients had normal liver function tests and only 3 had clinical evidence of jaundice. Ductal exploration and stone extraction was successful in all 16 patients. One patient required a direct laparoscopic ductal exploration due to the presence of a common hepatic duct stone and the anatomy of the cystic duct. No major complications or deaths were observed in this series. Appropriately trained surgeons can safely and effectively perform laparoscopic common bile duct exploration and stone extraction in selected patients.

Adult↗

PubMed2001

Tactile apraxia: unimodal apractic disorder of tactile object exploration associated with parietal lobe lesions.

Tactile apraxia is characterized by an isolated disturbance of hand movements for use of and interaction with an object (transitive movements) in the presence of preserved intransitive movements (movements without use of an object, for example repetitive movements or gestures). It is, however, still unclear whether motor and sensory abnormalities represent causal or associated features of tactile apraxia. To address this question, quantitative kinematic recordings of exploratory finger movements (transitive movements) and rapid alternating finger movements (intransitive movements) were studied in 20 healthy volunteers and 22 patients with focal lesions of the parietal, anterofrontal and motor cortex. The most severe deficits of manual object exploration were found in patients with parietal lesions, using the hand contralateral to the lesion. Patients with lesions of the anterior parietal lobe who exhibited prominent sensory deficits and astereognosia showed a decrease in frequency and regularity of exploratory finger movements and a marked increase in exploration space. Patients with posterior parietal lesions exhibiting severe astereognosia, apraxia and deficits in dexterity had a greater decrease in frequency and regularity of manipulative movements, but a less pronounced increase of exploration space than the patients with anterior parietal lesions. Although the patients with parietal lobe lesions could generate rapid alternating finger movements, the regularity of these movements was also impaired. In comparison, patients with frontal lobe lesions exhibited impaired contralesional manipulatory and rapid alternating finger movements but no sensory abnormalities or astereognosia. We conclude that tactile apraxia represents a deficit in the programming of exploratory finger movements mediated by the parietal lobe. The comparison with lesions of other regions participating in the cortical network for tactile exploration reveals that apraxia of exploratory movements in parietal lobe lesions represents a disturbance distinct from elementary motor or sensory abnormalities, but closely related to stereognostic functioning.

Adolescent↗

PubMed2003

Visual exploration behaviour during clock reading in Alzheimer's disease.

Eye movement behaviour during visual exploration of 24 patients with probable Alzheimer's disease and 24 age-matched controls was compared in a clock reading task. Controls were found to focus exploration on distinct areas at the end of each clock hand. The sum of these two areas of highest fixation density was defined as the informative region of interest (ROI). In Alzheimer's disease patients, visual exploration was less focused, with fewer fixations inside the ROI, and the time until the first fixation was inside the ROI was significantly delayed. Changes of fixation distribution correlated significantly with the ability to read the clock correctly, but did not correlate with dementia severity. In Alzheimer's disease patients, fixations were longer and saccade amplitudes were smaller. The altered visual exploration in Alzheimer's disease might be related to parietal dysfunction or to an imbalance between a degraded occipito-parietal and relatively preserved occipito-temporal visual network.

Aged↗

PubMed2006

The neural correlates of human working memory for haptically explored object orientations.

Skillful object manipulation requires that haptically explored spatial object characteristics like orientation be adequately represented in working memory. In the current functional magnetic resonance imaging study, healthy right-handed participants explored a bar-shaped reference object with the left hand, memorizing its orientation. After a variable delay (0.5, 5, or 10 s), participants used their right hand to match the orientation by rotating a second, identical object. In the first seconds of the delay, right sensorimotor cortex was active, whereas clusters in left anterior prefrontal cortex (aPFC) (Brodmann area 10) became dominant 2 s after the end of exploration, showing sustained activity for several seconds. In contrast, left parieto-occipital cortex was involved toward the end of the delay interval. Our results indicate that a dynamic network of brain areas subserves hapticospatial information processing in the delay between haptic stimulus exploration and orientation matching. We propose that haptic sensory traces, maintained in contralateral sensorimotor cortex, are transformed into more abstract hapticospatial representations in the early delay stages. Maintenance of these representations engages aPFC and parieto-occipital cortex. Whereas aPFC possibly integrates spatial and motor components of hapticospatial working memory, parieto-occipital cortex might be involved in orientation imagery, supporting working memory, and the preparation of haptic matching.

Adult↗

PubMed2002

Secondhand management of "spaghetti wrist": do not hesitate to explore.

"Spaghetti wrist" consists of the severance of at least three structures, of which one is the median nerve or the ulnar nerve, and it is one of the most devastating injuries of the hand. Close follow-up and appropriate rehabilitation are mandatory for management; however, this is not easy in patients whose previous treatment was accomplished elsewhere. The authors explored 28 patients with spaghetti wrist injuries who were previously operated. The study included those with areas of the hand, innervated by the injured nerve, that were partially or completely anesthetic. Limited sensorial return was also uniform and partial anesthetic sites were usually limited to only a finger or either side of a finger. When explored, six nerves had a normal appearance and 18 nerves had neuroma-in-continuity on their repair sites. The median nerves of the remaining five patients had been repaired not to their original proximal or distal stumps, but to adjacent tendons. A nerve tissue bridge from the proximal to the distal stump developed in all these patients. The authors conclude that hand surgeons should explore the previous repair sites if they have any suspicions regarding the technique performed and the success of previous management of spaghetti wrist. Any partial sensorial return to a limited area may be the result of axonal secondary pathways; thus, early exploration during the critical period can protect these patients from paralyzing sequelae of the injured nerves.

Adolescent↗

PubMed1977

Parathyroid re-exploration. A clinical and pathological study of 112 cases.

In a series of 112 patients who underwent reoperation for primary hyperparathyroidism at the Massachusetts General Hospital between 1930 and 1975, all but 10 were treated successfully. Seventy-five initial explorations had been performed elsewhere, and 37 in our hospital. A total of 110 diseased parathyroids were uncovered-89 (81%) via re-exploration of the neck and 21 (19%) via mediastinotomy. In operation via the neck, the missing glands were most frequently found in the superior posterior mediastinum at the thoracic inlet (34, or 38%) and in mediastinal exploration, in the upper anterior mediastinum (14, or 67%). There were 66 patients with adenoma, 7 with carcinoma, and 29 with primary hyperplasia. Four had a hyperfunctioning fifth gland. One patient had an intrathyroidal and one, an ectopic gland. Reoperation was unsuccessful in 10 patients. Four died, and 6 are living. Unsuccessful exploration resulted from failure to understand the widespread distribution of normal parathyroids and the way they were displaced when diseased, error in diagnosing the pathologic entity of hyperparathyroidism at surgery, and technical incompetence. Reoperation of the neck was generally performed first. A mediastinotomy was undertaken only if the missing gland was clearly excluded from the neck or if localization studies had demonstrated its presence beyond doubt in the mediastinum. Reoperation was rarely performed simultaneously on the neck and the mediastinum, and it was seldom indicated in asymptomatic cases with a mild degree of the disease.

Adenoma↗

PubMed1983

Stab wounds of the anterior abdomen. Analysis of a management plan using local wound exploration and quantitative peritoneal lavage.

A management plan for stab wounds to the anterior abdomen incorporating local wound exploration and quantitative peritoneal lavage was applied to 572 patients. One hundred eighty-five of these patients presented with shock, peritonitis, or evisceration and underwent immediate exploratory laparotomy with the finding of an intraperitoneal organ injury in 183 (99%). The remaining 387 patients with a negative physical examination underwent exploration of the stab wound to determine fascial penetration. Wound exploration was negative in 151 of these patients and they were discharged from the emergency room. Two hundred thirty-six additional patients had penetration of the fascia and underwent peritoneal lavage. Ninety-two per cent of patients with lavage counts greater than 50,000 had an intraperitoneal organ injury. No patients with lavage counts less than 1,000 red cells had an organ injury. Forty-three per cent of patients in the intermediate group (1,000-50,000 RBCs/mm3) had an organ injury and 59% included penetration of a hollow viscus. An approach incorporating local wound exploration and quantitative peritoneal lavage followed by exploratory laparotomy for red blood cell counts greater than 1,000 should result in less than 10% negative laparotomies and no missed injuries.

Abdominal Injuries↗

PubMed2000

One hundred consecutive minimally invasive parathyroid explorations.

OBJECTIVE: To review the outcomes of 100 consecutive minimally invasive parathyroid explorations. SUMMARY BACKGROUND DATA: Minimally invasive parathyroidectomy (MIP) has challenged the traditional approach of bilateral neck exploration for patients with primary hyperparathyroidism. Most patients with primary hyperparathyroidism have a single adenoma that when resected results in cure. It therefore appears logical to perform a directed approach to adenoma extirpation. MIP involves high-quality sestamibi images obtained with single photon emission computed tomography to localize enlarged parathyroid glands in three dimensions, limited exploration after surgeon-administered cervical block anesthesia, rapid intraoperative parathyroid hormone assay to confirm the adequacy of resection, and discharge within 1 to 3 hours of surgery. METHODS: MIP was offered to 100 selected consecutive patients during an 18-month period beginning in March 1998. RESULTS: Ninety-two cases were accomplished under cervical block anesthesia and 89 of these on an ambulatory basis. The cure rate was 100%, and there were no long-term complications. The mean hospital charge for MIP was less than 40% of that associated with traditional exploration. CONCLUSIONS: Outpatient MIP appears to be the procedure of choice for most patients with primary hyperparathyroidism.

Adenoma↗

PubMed1990

Exploration of the orbital floor: an indicated procedure?

Fractures to the middle third of the facial skeleton continue to increase in frequency secondary to motor vehicle accidents and interpersonal violence. Orbital floor fractures can occur either independently or may be associated with other facial bone fractures. Controversy has persistently surrounded the treatment of fractures to the floor of the orbit. We will present our investigation of 296 patients who sustained a total of 396 traumatic injuries to the orbit and were treated at the University of California, Davis Medical Center, Sacramento, California, during the period July 1, 1988 to June 30, 1989 to determine whether surgical exploration of the orbital floor is necessary or adds potential serious risks. In the 38 patients (46 orbits) who did not undergo surgical exploration of the orbital floor, 31 (82%) suffered serious residual complications. In the remaining group of 258 patients who underwent orbital floor exploration, there was a 7 percent incidence (18 patients) with residual sequelae. We conclude that exploration of the orbital floor has the potential to decrease the incidence of serious post-traumatic complications significantly, primarily enophthalmos.

Adult↗

PubMed1998

Tactile exploration of peripersonal space in patients with neglect.

Recent studies investigated the pattern of visual exploration along the horizontal axis in patients with neglect. They found a deviated distribution of activity with the centre shifted -15 degrees to the right of the body's mid-sagittal plane. The present study reports comparable observations concerning tactile exploration of space in neglect. We found the whole distribution of patients' exploratory hand movements shifted towards the right. The median activity lay 17.7 cm right of the body's mid-sagittal plane. The frequency of tactile exploration decreased towards the periphery of peripersonal space on the right and the left side. The findings are in clear contrast to the predictions of the attentional gradient model of neglect. They rather favour a deviation of the whole frame for exploratory behaviour towards a new equilibrium on the right. The character of this frame appears to be supramodal in that it determines the distribution of exploratory movements irrespective of whether the subject explores the surround visually or tactually.

Aged↗

PubMed1999

Arctic and Antarctic exploration including the contributions of physicians and effects of disease in the polar regions.

A history of Arctic and Antarctic exploration, whether to find a Northwest Passage, North Pole, or South Pole, is a story of triumph and tribulation. The hardship experienced by polar explorers in the last 1000 years permeates the tales of achievement. Physicians and surgeons have played prominent roles in all major polar explorations. No significant Arctic voyage, particularly in the last 300 years, was made without a member of the party trained in the management of medical emergencies and in basic surgery. During times of health, surgeons functioned as the voyage naturalists with expertise in biology, botany, zoology, and the writing of scientific catalogs. Spurred by our interest and fascination with the history of polar exploration, we reviewed the roles of physicians and natural scientists in Arctic and Antarctic adventures.

Antarctic Regions↗

PubMed2006

A prospective randomized study of posterolateral lumbar fusion using osteogenic protein-1 (OP-1) versus local autograft with ceramic bone substitute: emphasis of surgical exploration and histologic assessment.

STUDY DESIGN: A prospective, randomized and controlled study. OBJECTIVES: To evaluate the osteoinductive property of Osteogenic Protein-1 (OP-1 or BMP-7) and fusion rate in human instrumented posterolateral lumbar fusion through radiographic examination, surgical exploration, and histologic assessment. SUMMARY OF BACKGROUND DATA: The use of osteoinductive agents is a current topic in spinal fusion. Numerous preclinical investigations have demonstrated efficacy of osteoinductive proteins in spinal fusion, but few human clinical studies have been reported. METHODS: Nineteen patients with L3-L4 or L4-L5 degenerative spondylolisthesis underwent posterolateral lumbar fusion using pedicle screw instrumentation. The patients were randomized to receive either OP-1 Putty (3.5 mg OP-1/g of collagen matrix per side) alone (n = 9), or local autograft with HA-TCP granules (n = 10). Fusion status was evaluated using plain radiography and CT scan. Radiographic fusion criteria included less than 5 degrees of angular motion, less than 2 mm of translation, and evidence of bridging bone in the posterolateral lumbar area in which the graft materials were placed following decortication. After a minimum 1-year follow-up, the patients who showed radiographic evidence of fusion underwent instrumentation removal and surgical exploration of the fusion site. Biopsy specimens were taken from the fusion mass and evaluated histologically. RESULTS: Radiographic fusion rate was 7 of 9 OP-1 patients and 9 of 10 control patients. Based on surgical exploration of these 16 patients, new bone formation was macroscopically observed in the posterolateral lumbar region in all cases; however, solid fusion was observed in 4 of 7OP-1 and 7 of 9 HA-TCP/autograft patients. Histologic assessment demonstrated viable bone in 6 of 7 OP-1 patients. All the control (HA-TCP/autograft) specimens contained viable bone and fibrous tissue surrounding ceramic granules, suggesting slow incorporation of the graft material. CONCLUSIONS: In a human posterolateral lumbar spine trial, OP-1 reliably induced viable amounts of new bone formation, but the fusion success rate evaluated by surgical exploration was only 4 of 7.

Aged↗

PubMed2005

Clinical and histological significance of the testicular remnant found on inguinal exploration after diagnostic laparoscopy in the absence of a patent processus vaginalis.

PURPOSE: We reviewed the histological findings of cord structures excised at inguinal exploration after diagnostic laparoscopy in patients with a nonpalpable testis with the vas deferens and spermatic vessels exiting the internal inguinal ring in the absence of a patent processus vaginalis. MATERIALS AND METHODS: A retrospective review of 809 laparoscopic explorations for nonpalpable testes between 1981 and 2003 was conducted. The histological findings of the excised remnants of those patients with a closed processus vaginalis were reviewed. RESULTS: A total of 110 patients underwent excision of a testicular remnant at inguinal exploration in association with a closed processus vaginalis. Of the specimens 31 (28%) were on the right side and 79 (72%) were on the left side. The incidence of viable germ cell elements was 8 of 110 (7%). The presence of hemosiderin, calcification and fibrosis was identified in all 8 remnants with viable germ cell elements. CONCLUSIONS: The incidence of viable germ cell elements in the excised remnant when the vas deferens and spermatic vessels are identified exiting a closed internal ring in patients with a nonpalpable testis is 7%. To our knowledge no prior study has evaluated the incidence of viable germ cell elements in remnants associated with a closed internal inguinal ring. Based on these findings, we advocate inguinal exploration and excision of testicular remnants in these patients.

Adolescent↗

PubMed2006

Space re-exploration in hemispatial neglect.

Exploration of the space around us is a fundamental part of human behaviour. When it breaks down there is an important opportunity to understand its underlying mechanisms. Here we show that many right-hemisphere patients with left neglect re-explore rightward locations, failing to keep track of them during search. Importantly, such re-exploration occurred despite leftward stimuli being indistinguishable in peripheral vision, so it is unlikely to result from implicit processing of neglected targets. Revisits generally occurred after visits to other targets and are therefore not immediate perseverations. Finally, manipulating the visual salience of found targets altered the degree of neglect, but not revisit rates. Space exploration appears to be modulated both by the ability to keep track of spatial locations and by stimulus salience.

Aged↗

PubMedDate not supplied

Provenance and annotation for visual exploration systems.

Exploring data using visualization systems has been shown to be an extremely powerful technique. However, one of the challenges with such systems is an inability to completely support the knowledge discovery process. More than simply looking at data, users will make a semipermanent record of their visualizations by printing out a hard copy. Subsequently, users will mark and annotate these static representations, either for dissemination purposes or to augment their personal memory of what was witnessed. In this paper, we present a model for recording the history of user explorations in visualization environments, augmented with the capability for users to annotate their explorations. A prototype system is used to demonstrate how this provenance information can be recalled and shared. The prototype system generates interactive visualizations of the provenance data using a spatio-temporal technique. Beyond the technical details of our model and prototype, results from a controlled experiment that explores how different history mechanisms impact problem solving in visualization environments are presented.

Algorithms↗

PubMedDate not supplied

Balancing systematic and flexible exploration of social networks.

Social network analysis (SNA) has emerged as a powerful method for understanding the importance of relationships in networks. However, interactive exploration of networks is currently challenging because: (1) it is difficult to find patterns and comprehend the structure of networks with many nodes and links, and (2) current systems are often a medley of statistical methods and overwhelming visual output which leaves many analysts uncertain about how to explore in an orderly manner. This results in exploration that is largely opportunistic. Our contributions are techniques to help structural analysts understand social networks more effectively. We present SocialAction, a system that uses attribute ranking and coordinated views to help users systematically examine numerous SNA measures. Users can (1) flexibly iterate through visualizations of measures to gain an overview, filter nodes, and find outliers, (2) aggregate networks using link structure, find cohesive subgroups, and focus on communities of interest, and (3) untangle networks by viewing different link types separately, or find patterns across different link types using a matrix overview. For each operation, a stable node layout is maintained in the network visualization so users can make comparisons. SocialAction offers analysts a strategy beyond opportunism, as it provides systematic, yet flexible, techniques for exploring social networks.

Algorithms↗

PubMed2007

Vaginal birth after caesarean section (VBAC): exploring women's perceptions.

AIMS AND OBJECTIVES: This study was designed to complement local audit data by examining the lived experience of women who elected to attempt a vaginal birth following a previous caesarean delivery. The study sought to determine whether or not women were able to exercise informed choice and to explore how they made decisions about the method of delivery and how they interpreted their experiences following the birth. BACKGROUND: The rising operative birth rate in the UK concerns both obstetricians and midwives. Although the popular press has characterized birth by caesarean section as the socialites' choice, in reality, maternal choice is only one factor in determining the method of birth. However, in considering the next delivery following a caesarean section, maternal choice may be a significant indicator. While accepted current UK practice favours vaginal birth after caesarean (VBAC) in line with the research evidence indicating reduced maternal morbidity, lower costs and satisfactory neonatal outcomes, Lavender et al. point out that partnership in choice has emerged as a key factor in the decision-making process over the past few decades. Chaung and Jenders explored the issue of choice in an earlier study and concluded that the best method of subsequent delivery, following a caesarean birth, is dependent on a woman's preference. DESIGN AND METHODOLOGY: Using a phenomenological approach enabled a holistic exploration of women's lived experiences of vaginal birth after the caesarean section. RESULTS: This was a qualitative study and, as such, the findings are not transferable to women in general. However, the results confirmed the importance of informed choice and raised some interesting issues meriting the further exploration. CONCLUSIONS: Informed choice is the key to effective women-centred care. Women must have access to non-biased evidence-based information in order to engage in a collaborative partnership of equals with midwives and obstetricians. RELEVANCE TO CLINICAL PRACTICE: This study is relevant to clinical practice as it highlights the importance of informed choice and reminds practitioners that, for women, psycho-social implications may supersede their physical concerns about birth.

Decision Making↗