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At least 163 records · Page 9Linked to original sources

Bilateral neck exploration under hypnosedation: a new standard of care in primary hyperparathyroidism?

OBJECTIVE: The authors review their experience with initial bilateral neck exploration under local anesthesia and hypnosedation for primary hyperparathyroidism. Efficacy, safety, and cost effectiveness of this new approach are examined. BACKGROUND: Standard bilateral parathyroid exploration under general anesthesia is associated with significant risk, especially in an elderly population. Image-guided unilateral approaches, although theoretically less invasive, expose patients to the potential risk of missing multiple adenomas or asymmetric hyperplasia. Initial bilateral neck exploration under hypnosedation may maximize the strengths of both approaches while minimizing their weaknesses. METHODS: In a consecutive series of 121 initial cervicotomies for primary hyperparathyroidism performed between 1995 and 1997, 31 patients were selected on the basis of their own request to undergo a conventional bilateral neck exploration under local anesthesia and hypnosedation. Neither preoperative testing of hypnotic susceptibility nor expensive localization studies were done. A hypnotic state (immobility, subjective well-being, and increased pain thresholds) was induced within 10 minutes; restoration of a fully conscious state was obtained within several seconds. Patient comfort and quiet surgical conditions were ensured by local anesthesia of the collar incision and minimal intravenous sedation titrated throughout surgery. Both peri- and postoperative records were examined to assess the safety and efficacy of this new approach. RESULTS: No conversion to general anesthesia was needed. No complications were observed. All the patients were cured with a mean follow-up of 18 +/- 12 months. Mean operating time was <1 hour. Four glands were identified in 84% of cases, three glands in 9.7%. Adenomas were found in 26 cases; among these, 6 were ectopic. Hyperplasia, requiring subtotal parathyroidectomy and transcervical thymectomy, was found in five cases (16.1%), all of which had gone undetected by localization studies when requested by the referring physicians. Concomitant thyroid lobectomy was performed in four cases. Patient comfort and recovery and surgical conditions were evaluated on visual analog scales as excellent. Postoperative analgesic consumption was minimal. Mean length of hospital stay was 1.5 +/- 0.5 days. CONCLUSIONS: Initial bilateral neck exploration for primary hyperparathyroidism can be performed safely, efficiently, and cost-effectively under hypnosedation, which may therefore be proposed as a new standard of care.

Adult↗

Six hundred fifty-six consecutive explorations for primary hyperparathyroidism.

OBJECTIVE: To review the outcomes of 656 consecutive parathyroid explorations performed by a single surgeon and to compare the results of conventional and minimally invasive parathyroidectomy (MIP) techniques. SUMMARY BACKGROUND DATA: Traditional surgery for primary hyperparathyroidism (HPTH) involves bilateral cervical exploration, which is usually accomplished under general endotracheal anesthesia. The MIP technique involves preoperative localization with sestamibi scans, surgeon-administered cervical block anesthesia, directed exploration through a small incision, intraoperative rapid parathyroid hormone assay, and discharge within 2 to 3 hours of surgery. METHODS: Six hundred fifty-six consecutive patients with primary HPTH underwent exploration between January 1990 and March 2001. RESULTS: MIP was used with ever-increasing frequency beginning in March 1998. Four hundred one procedures (61%) were performed using the standard technique and 255 patients (39%) were selected for MIP. The success rate for the entire series was 98%, with no significant differences comparing traditional and MIP techniques. The overall complication rate of 2.3% reflects 3.0% and 1.2% rates in the standard and MIP groups, respectively. MIP was associated with approximately a 50% reduction in operating time, a sevenfold reduction in length of hospital stay, and a mean cost savings of $2,693 per procedure, which represents nearly a 50% reduction in total hospital charges. CONCLUSIONS: A dramatic and sustained shift has occurred in the surgical treatment of primary HPTH: MIP has replaced traditional exploration for most patients.

Cost Savings↗

Is contralateral exploration of the kidney necessary in patients with Wilms tumor?

PURPOSE: Surgical exploration of the contralateral kidney in patients with Wilms tumor is standard practice. The introduction of modern imaging techniques (ultrasound, computerized tomography and magnetic resonance imaging) in place of excretory urography has led to a more accurate definition of intrarenal pathology. Is contralateral kidney exploration still necessary in patients with Wilms tumor? MATERIALS AND METHODS: We reviewed the records of 75 patients from 3 medical centers who were evaluated and treated for Wilms tumor in the last 14 years. All children underwent preoperative excretory urography, computerized tomography, ultrasound and/or magnetic resonance imaging. RESULTS: Seven bilateral Wilms tumors were diagnosed preoperatively and confirmed surgically, whereas extensive operative exploration of the contralateral kidney in the other 69 patients revealed no additional pathological condition. This concurred with preoperative radiological findings with 100% sensitivity and specificity. Furthermore, 1 month to 12 years of followup (mean 4.3 years) revealed no tumor in the contralateral kidney. The major postoperative complication was small bowel obstruction in 5 patients 15 to 180 days (mean 77.2) after explorative laparotomy. CONCLUSIONS: In all patients preoperative radiological investigation was accurate in excluding bilaterality. With modern imaging techniques and effective chemotherapy extensive contralateral renal exploration may no longer be mandatory for managing Wilms tumor.

Adolescent↗

Exploration for testicular remnants: implications of residual seminiferous tubules and crossed testicular ectopia.

PURPOSE: Testicular remnants identified during exploration for cryptorchidism contain vascularized fibrous nodules at the termination of the vas deferens, hemosiderin, calcification, a pampiniform plexus or occasionally residual seminiferous tubules that may contain germ cells. An absent testis lacks the features of testicular remnants. To our knowledge testicular remnants have not been described in a crossed ectopic location. We reviewed orchiectomy specimens obtained at exploration for a nonpalpable testis to characterize the features of testicular remnants, including the frequency of seminiferous tubules, germ cells and crossed ectopia, as well as to clarify the diagnostic criteria for testicular remnants. MATERIALS AND METHODS: From 1990 to mid 2000 medical records and histological slides from 101 boys with nonpalpable testes who had undergone inguinal exploration and orchiectomy were reviewed. RESULTS: Of the 71 testicular remnants identified 7 (9.8%) contained residual tubules, of which 4 (5.6%) contained germ cells. In 4 boys the testis was deemed absent but 3 did not undergo laparoscopic exploration. There were 2 ectopic remnants (2.8%) on the contralateral side-the pelvis or in the scrotum. Both crossed remnants demonstrated dissociation of the testis from the vas/epididymis which remained on the correct side associated with a pampiniform plexus. No müllerian remnants were encountered. CONCLUSIONS: Adequate exploration for nonpalpable testis requires laparoscopy with visualization of the contralateral pelvic region because an ectopic remnant may be dissociated from the vas/epididymis and vessels. Identification of a pampiniform plexus, vas and spermatic vessels may not be a reliable indicator of a testicular remnant. Continued removal of testicular remnants is warranted because at least 9.8% contain residual viable tubules.

Child↗

Blind children recognizing tactile pictures respond like sighted children given guidance in exploration.

Theory of tactile pictures argues that untrained blind subjects can recognize raised, outline pictures. It contends the blind person's knowledge of the shapes of common objects is like that of the sighted, and the blind person's pictorial abilities use the same principles as the sighted person's. To test this theory, blind children (aged 8-13) and blindfolded age-matched sighted children were asked to identify raised-line drawings of common objects. Their performances were correlated. In addition, the blind children identified more than sighted children exploring the pictures actively, but the same number of pictures as sighted children who were given passive, guided exploration. We argue blind and sighted children use the same principles to identify the pictures, but the blind have superior exploration skills. The differences in the effects of exploration skills on recognition scores are minimized when the sighted children are given guidance, since the sighted children then have efficient contact with the displays, and the performance of the sighted and the blind is then governed by the same principles, without one group benefitting from advantages in exploration skills.

Adolescent↗

Exploration of surface-textures in congenitally blind infants.

The haptic exploratory procedures that eight congenitally blind infants aged 8-24 months used to explore a gradient surface texture were investigated. Exploration of the gradient texture was examined over five sessions with 2 weeks between sessions, followed after 1 week by a sixth session, in which exploration of the gradient texture was compared to exploration of two other textures. Results showed that the infants have a wide range of exploratory strategies available and that the older infants can use these strategies in a specific manner. Results are discussed with reference to current ideas about the exploratory possibilities of congenitally blind infants. Use of texture in the stimulation of exploration of blind infants is discussed.

Blindness↗

Initial parathyroid exploration: current trends in Australia.

BACKGROUND: An Australia-wide multicentre prospective study was undertaken to audit cases of initial parathyroid exploration between 1 January and 31 December 1992. One hundred and sixty-two cases were audited. The audit was designed to study pre-operative biochemical assessment, localization techniques and the technique of exploration. METHOD: A pro forma audit form was circulated to all Australian surgeons known to perform parathyroid surgery. Eleven responded. RESULTS: Free serum ionized calcium (iCa) was measured in 30% of cases, with the majority of pre-operative calcium assays being performed using total serum calcium (tCa). In 40 cases (29%) pre-operative localization techniques were used. These proved inaccurate in 10 cases. The intra-operative technique of localization with methylene blue infusion was used in 11% of cases. All four glands were biopsied in 11% of cases. No deaths were reported and a postoperative morbidity rate of 3.1% was noted. Eighty-eight per cent of patients were discharged within 5 days of surgery with a third going home within 48 h of neck exploration surgery. Only one patient (0.6%) required re-exploration for persistent hypercalcaemia due to a second adenoma. CONCLUSIONS: The surgical treatment of hyperparathyroidism can be regarded as safe, with minimum morbidity in experienced hands. Pre-operative localization studies in initial parathyroid exploration are not indicated.

Adolescent↗

Exploration and mating range in African Pygmies.

The distributions of exploration range and of mating range were studied among Aka Pygmies of the Central African Republic. Exploration range is defined and methods of estimation for single individuals suggested. A simple exponential distribution is found for individual Aka Pygmies, with variation of exploration range (the parameter defining mobility) with sex, age and ethnic affiliation. Distribution of distances from birthplace and place of residence are compared and show modest differences. The frequency of visits to a given place has also been studied. The average distance between birthplaces of mates is very similar to the mean exploration range. Correlations between individual exploration and mating ranges suggest that it is the male who may be choosing a marriage partner among Pygmies. A theory by Boyce, Küchemann & Harrison (1967) on the relations between "neighbourhood knowledge" and mating distance is inapplicable because of its reliance on the Pareto distribution, which does not apply in the present case, and of other unnecessary assumptions, but the general principle of a close relationship between exploratory activity and mating distance seems valid, at least in the present case. Suggestions are made for causes for the difference between the present distributions and those with other shapes observed in less primitive economies.

Adult↗

Geovisualization to support the exploration of large health and demographic survey data.

BACKGROUND: Survey data are increasingly abundant from many international projects and national statistics. They are generally comprehensive and cover local, regional as well as national levels census in many domains including health, demography, human development, and economy. These surveys result in several hundred indicators. Geographical analysis of such large amount of data is often a difficult task and searching for patterns is particularly a difficult challenge. Geovisualization research is increasingly dealing with the exploration of patterns and relationships in such large datasets for understanding underlying geographical processes. One of the attempts has been to use Artificial Neural Networks as a technology especially useful in situations where the numbers are vast and the relationships are often unclear or even hidden. RESULTS: We investigate ways to integrate computational analysis based on a Self-Organizing Map neural network, with visual representations of derived structures and patterns in a framework for exploratory visualization to support visual data mining and knowledge discovery. The framework suggests ways to explore the general structure of the dataset in its multidimensional space in order to provide clues for further exploration of correlations and relationships. CONCLUSION: In this paper, the proposed framework is used to explore a demographic and health survey data. Several graphical representations (information spaces) are used to depict the general structure and clustering of the data and get insight about the relationships among the different variables. Detail exploration of correlations and relationships among the attributes is provided. Results of the analysis are also presented in maps and other graphics.

Journal Article↗

The impact of mental fatigue on exploration in a complex computer task: rigidity and loss of systematic strategies.

We investigated the impact of mental fatigue on exploration in a complex computer task. The exploration behavior of participants who underwent a fatigue manipulation (N = 36) was compared with that of a control (nonfatigued) group (N = 32). A distinction was also made between participants with high or low levels of general computer experience. Results showed that fatigued participants used significantly less systematic exploration and made more errors than did nonfatigued participants. Fatigued participants with low computer experience also showed significantly more rigid behavior than did the other participants. No differences were found on the number of subtasks solved. Compared with low-experience participants, highly experienced participants showed significantly more systematic exploration, less unsystematic trial and error, solved more subtasks, and made fewer errors (marginally significant p = .056). Findings were interpreted as the result of reduced task engagement under fatigue and reduced involvement of executive control on behavior. Actual or potential applications of this research include guidelines to prevent detrimental effects of mental fatigue on exploration behavior.

Adult↗

The effectiveness of InGaAsP diode laser radiation to detect subgingival calculus as compared to an explorer.

BACKGROUND: The aim of the present study was to compare the ability of the diode laser to detect residual calculus with that of an explorer. METHODS: The root surface of 40 extracted human teeth, each partially covered with subgingival calculus, was instrumented with curets under simulated clinical conditions in a manikin. The samples were randomly assigned to two study groups. In group A, the root surface was treated with an explorer until it appeared free of mineralized deposits upon examination. The samples in group B were instrumented until the relative intensity of fluorescence as induced with diode laser radiation was below a threshold value of 5. The root surface of each sample was then examined for residual calculus using standardized digital images. The statistical analysis was performed with a non-paired t test at a level of significance of 5% (P < 0.05). RESULTS: The root surface of single-rooted teeth showed residual calculus on 0.19 +/- 0.37 x 10(7) microm2 in the laser group and on 0.11 +/- 0.26 x 10(7) microm2 in the explorer group (P = 0.19). For multirooted teeth, the mean calculus-covered area was 0.50 +/- 0.48 x 10(7) microm2 for the teeth evaluated with an explorer and 0.27 +/- 0.43 x 10(7) microm2 for the diode laser group (P = 0.02). CONCLUSION: The present findings indicate that the detection of subgingival calculus is significantly improved using 655 nm diode laser radiation compared to an explorer for molars but not for single-rooted teeth.

Arsenic↗

The effects of NMDA antagonists on punished exploration in mice.

Previous studies have reported that several NMDA antagonists show anxiolytic-like activity in behavioural tests. To follow up the observation that AP7 increased the punished exploration of mice in the four plate test, several NMDA antagonists were tested in this procedure in shocked and non-shocked conditions. AP7 increased shocked exploration without increasing non-shocked exploration. However, another competitive NMDA antagonist, CGS 19755, produced no increases in exploration in either condition. The non-competitive antagonists, phencyclidine, MK-801 and dextromethorphan, produced dose-related increases in activity in both the non-shocked and shocked conditions. This effect is probably best considered a psychomotor stimulant action rather than an anxiolytic-like activity. The non-competitive NMDA antagonist, SL 82.0715, which acts at the polyamine site, and the ethyl ester of 7-chlorokynurenic acid, which acts at the glycine modulatory site, produced only decreases in exploration indicating that they lack both stimulant and anxiolytic activity. Although providing little evidence for anxiolytic action the present results further demonstrate that compounds acting at different sites within the NMDA receptor complex can give rise to very different pharmacological and behavioural effects.

Journal Article↗

[Peroperative exploration of the liver in hepatic tumor surgery].

Intraoperative exploration of the liver and complete abdominal examination are essential before hepatic resection for patients with liver tumors. The surgeon's eye and hand, traditional methods of exploration, are still accurate for abdominal exploration, screening of small superficial liver tumors and evaluation of non-tumoral liver parenchyma. Intraoperative ultrasonography is often superior to preoperative screening methods in diagnosing small liver tumors. Intraoperative ultrasonography identifies variations of intrahepatic vascular structures and reveals exact location of tumors according to functional anatomy. The surgeon's eye and hand and intraoperative ultrasound are complementary for a complete exploration, and may affect operative decision making. Laparoscopy and laparoscopic ultrasonography, when diagnosing non resectable tumors, reduce the number of unnecessary laparotomies. However, the effectiveness of exploration by laparoscopy and laparoscopic ultrasonography is lower than that of laparotomy, which remains indispensable before hepatic resection for malignant tumors.

Dissection↗

An Antarctic research outpost as a model for planetary exploration.

During the next 50 years, human civilization may well begin expanding into the solar system. This colonization of extraterrestrial bodies will most likely begin with the establishment of small research outposts on the Moon and/or Mars. In all probability these facilities, designed primarily for conducting exploration and basic science, will have international participation in their crews, logistical support and funding. High fidelity Earth-based simulations of planetary exploration could help prepare for these expensive and complex operations. Antarctica provides one possible venue for such a simulation. The hostile and remote dry valleys of southern Victoria Land offer a valid analog to the Martian environment but are sufficiently accessible to allow routine logistical support and to assure the relative safety of their inhabitants. An Antarctic research outpost designed as a planetary exploration simulation facility would have great potential as a testbed and training site for the operation of future Mars bases and represents a near-term, relatively low-cost alternative to other precursor activities. Antarctica already enjoys an international dimension, an aspect that is more than symbolically appropriate to an international endeavor of unprecedented scientific and social significance--planetary exploration by humans. Potential uses of such a facility include: 1) studying human factors in an isolated environment (including long-term interactions among an international crew); 2) testing emerging technologies (e.g., advanced life support facilities such as a partial bioregenerative life support system, advanced analytical and sample acquisition instrumentation and equipment, etc.); and 3) conducting basic scientific research similar to the research that will be conducted on Mars, while contributing to the planning for human exploration. (Research of this type is already ongoing in Antarctica).

Antarctic Regions↗

[Unilateral versus bilateral neck exploration in the surgery of primary hyperparathyroidism].

The aim of this study is to know the indications, advantages and disadvantages of a unilateral neck exploration versus bilateral in the primary hyperparathyroidism (HPT) surgery. Since april 1990 to april 2002 we have operated 80 patients diagnosed of HPT. They where divided in different groups in function of the results of the clinic exploration intact paratohormone results (PTHi turbo). In 48 patients (60%) we have done an unilateral cervical surgical exploration (in 9 cases we have determined the PTHi turbo) with good postoperative results. In 32 patients we have realised a bilateral exploration with exposition of both recurrent nerves, based on the discordance between the image exploration and because we were not able to have the intro-operative dose of turbo of PTHi, which use parameter we defend because of its contrasted efficiency, with less surgical time and less iatrogenic possibilities.

Female↗

Explorer sharpness as related to margin evaluations.

Nine experienced operative dentistry faculty each used six different explorers of varying degrees of sharpness ranging from new to well-used to evaluate marginal acceptability on a device used to simulate gradations of vertical opening. In this study, the standard for the sharpest explorer point was determined to be 68 microns in diameter measured 40 microns from the tip. There was a positive correlation between the diameter of the explorer tip at 40 microns and the mean amount of opening that could be detected until the margin was declared unacceptable. Increased explorer dullness significantly handicapped even experienced graders when the explorer alone was used to evaluate visually inaccessible margins.

Dental Instruments↗

Laparoscopic versus open surgical exploration in premenopausal women with suspected acute appendicitis.

OBJECTIVES: To assess the utility of laparoscopic versus conventional surgical exploration in premenopausal women with suspected acute appendicitis. METHOD: Female patients aged 15-45 years in whom an independent decision to undertake surgical exploration had been made, were randomised to laparoscopic or open procedures. Comparison of patient groups was conducted on an intention-to-treat basis. RESULTS: Eighteen patients underwent laparoscopic exploration, with 1 procedure requiring conversion to lower midline laparotomy. Open surgical exploration was performed primarily in 16 patients. Postoperative complications (3 patients versus 1 patient) and diagnostic errors (5 patients versus 1 patient) were more frequent in patients undergoing open surgical procedures. Laparoscopic procedures tended to be of longer duration than open operations, but were generally associated with slightly more favourable indices of postoperative recovery (analgesic requirement, postoperative hospitalisation, return to normal activity, return to work). In patients found not to have acute appendicitis, the difference in mean postoperative hospitalisation following laparoscopic intervention (2.6 days) and conventional surgery (3.4 days) approached statistical significance (p < 0.1). CONCLUSIONS: Laparoscopy may carry some diagnostic advantage over open surgery in premenopausal women with suspected acute appendicitis. Patients found not to have acute appendicitis have a marginally shorter period of hospitalisation after laparoscopic intervention. The outcome following laparoscopic appendicectomy for confirmed acute appendicitis is at least equivalent to that achieved with conventional appendicectomy. Laparoscopic exploration is an acceptable option in premonopausal women requiring surgery for suspected acute appendicitis.

Acute Disease↗

[Detection of thyroid pathology during surgical exploration of the neck for primary hyperthyroidism].

OBJECTIVE: Our objective was to determine prevalence of incidental thyroid pathology during surgical treatment of primary hyperparathyroidism and to compare sensitivity and specificity of surgical neck exploration with histologic study of resected thyroid gland to confirm unsuspected pathologies. MATERIAL AND METHODS: This was prospective cohort study performed at the Specialty Hospital's Department of Endocrine Surgery at the Mexican Institute of Social Security's (IMSS's) Centro Médico de Occidente in Guadalajara, Jalisco State between 1995 and 2003. All were submitted to bilateral neck exploration under general anesthesia. According to the surgeon's criteria, any suspected thyroid anomaly was resected for transoperative frozen sections as well as definite histopathologic study. RESULTS: Preoperatively from a total of 44 cases of hyperparathyroidism, only four cases with thyroid anomalies were detected with neck ultrasound and/or computer tomography (CT) scan; additionally, 13 patients had thyroid anomalies found during neck exploration according to surgeon criteria. All were biopsied. Final study revealed thyroid disease in 16 cases; three had well-differentiated thyroid carcinoma and the remaining 13 patients had different benign entities. In one case, the thyroid specimen was considered normal. Sensitivity and specificity of surgeon criteria were 100 and 96%, respectively, to establish thyroid disease during neck exploration for another purpose. CONCLUSIONS: Association of hyperparathyroidism and benign and malignant thyroid disease is a common phenomenon. Independently of the ability of preoperative imaging procedures to detect unsuspected findings, we suggest exploration neck bilaterally and resection of any suspicious lesion.

Adenocarcinoma, Follicular↗