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At least 235 records · Page 13Linked to original sources

PubMed2005

Hyperthyroidism after parathyroid exploration.

BACKGROUND: We hypothesized that hyperthyroidism after parathyroid exploration may be an underreported phenomenon with a course more severe than recognized previously. METHODS: We examined pre- and postoperative thyroid function and outcomes in 199 consecutive patients who, since March 2000, had parathyroid exploration for primary sporadic hyperparathyroidism (HPTH). We excluded patients with prior thyroid or parathyroid surgery, preoperative thyroid medication, concurrent total thyroidectomy, or follow-up <5 months. RESULTS: Of 125 patients with normal preoperative serum thyroid-stimulating hormone levels, 39 (31.2%) were hyperthyroid postoperatively. Mean thyroid-stimulating hormone levels (mean +/- SD) dropped with operation from 2.0 +/- 1.1 microIU/mL to 1.2 +/- 1.4 microIU/mL (P < .0001). Nineteen patients (15%) reported symptoms 1 to 2 weeks after operation. The clinical course of hyperthyroidism typically was short, but 5 patients (4%) had symptomatic hyperthyroxinemia requiring medical therapy. Hyperthyroidism was independent of age, severity of HPTH, anatomic/pathologic features, operative time, and other measures of operative difficulty, but was associated with lithium therapy, bilateral exploration, and absence of concurrent thyroid lobectomy. CONCLUSIONS: Risk of hyperthyroidism may be underappreciated after routine parathyroid surgery for HPTH. Use of lithium and degree of dissection appear contributory. Patients undergoing parathyroid exploration need counseling and surveillance for hyperthyroidism, which may be reduced by minimizing the extent of parathyroid surgery.

Adolescent↗

PubMed2005

Interactive dynamic graphical techniques for the exploration of functional data.

INTRODUCTION: The use of interactive dynamic graphics has become a common practice for the exploration of multidimensional data sets. The availability of powerful and inexpensive hardware and software for graphical computing makes the use of such techniques feasible for the examination of complex forms of data. This paper describes some simple techniques, which were implemented in the LISP-STAT environment, for the visualization of functional data arising from studies of optical technologies used for the detection of cervical intraepithelial neoplasia or squamous intraepithelial lesions. MATERIALS AND METHODS: The methods demonstrated have been implemented in software coded in LISP-STAT, a free statistical computing package available for most computer systems. The data used in this paper are drawn from a previous study in which fluorescence spectroscopy was measured from cervical sites at 337 nm, 380 nm, and 460 nm excitation in cervical screening patients. The goal of the project is to explore biographical variables to better understand the biology of fluorescence. RESULTS: 199 measurements were taken in 55 women with normal Pap smears. The data are recorded as spectra showing the intensity of emission excitation versus emission in nanometers. Covariate variables available for analysis are current smoker vs. nonsmoker premenopausal vs. postmenopausal, tissue type (columnar, squamous, and transition zone), and age in years. Although the optical measurements show consistent changes between normal and abnormal tissue in individual patients, there is wide variation in the intensity of the measurements between patients, even for normal tissue. Patient age affects the fluorescent spectrum showing increasing intensity with increasing age. Menopausal status affects the fluorescent spectra coincidentally with age. Smoking and race do not appear to affect the spectra in this sample of patients. CONCLUSIONS: The use of interactive graphical techniques permits the data analyst to examine multidimensional data in intuitive ways. These explorations allow non-statisticians to explore the data in a perceptive manner that may lead to new approaches in algorithm development for optical technologies.

Analysis of Variance↗

PubMed1994

Carotid exploration for acute postoperative thrombosis.

To determine the incidence of carotid reoperation and to document operative findings and clinical results, the records of patients requiring early reoperation (after less than 24 hours) during a 10-year period were analyzed with respect to operative findings, clinical outcome, and arterial patency. Endarterectomy was performed in 920 patients, with 27 strokes (3%) and 10 deaths (1%). Early re-exploration was required for 27 patients (3%) for either expanding hematoma (6 patients) or suspected thrombosis associated with a new neurologic deficit (21 patients). Two patients bled from the arteriotomy and 4 bled from surrounding tissues. Exploration for new postoperative neurologic events confirmed thrombosis in 19 cases (91%). Two patients with patent arteries and normal operative arteriograms were felt to have distal embolization, and the arteriotomy was not opened. Causes of thrombosis were intimal flap in 6 patients and closure stenosis in 11; the cause was unknown in 2 cases. All arteries were repaired over a shunt with a patch. Follow-up studies were available for 16 arteries, all of which remained patent. Of patients explored for hemorrhage, there was one death (from myocardial infarction), no neurologic events, and no late infections. Of 21 patients who underwent a second operation for neurologic deficits, 2 died, 8 were unchanged, 2 had minor residual deficit, and 9 had completely resolved deficits. Severe contralateral disease was more common among patients with residual deficits (10 of 12) compared with patients without residual deficits (0 of 9; chi-square = 8.23, P < 0.005). Carotid re-exploration is most commonly undertaken for a new neurologic deficit, usually associated with thrombosis at the operative site. Thrombosis is more often due to arterial narrowing than to an intimal defect. Prompt repair will restore patency and result in improvement in 50% of cases. Neurologic recovery is related to the status of the contralateral artery.

Acute Disease↗

PubMed1996

The value of computed tomography scan versus an explorative surgical approach for removal of squamous cell carcinoma of the posterior pharyngeal wall.

BACKGROUND: The prevertebral fascia plays a key role in surgery of posterior pharyngeal wall tumors. Invasion of the prevertebral muscles determines the irresectability of the tumor and accurate diagnosis of invasion posteriorly is a prerequisite for major ablative surgery. METHODS: A retrospective study was performed to define the value of CT scanning versus open neck exploration with regard to the resectability of posterior pharyngeal wall carcinoma. The predictive value of preoperative CT scans was assessed and compared with the outcome of open neck exploration and resectability of the primary tumor, using the final histopathology report as a gold standard. RESULTS: Nineteen patients with 20 tumors were included in this study. Overall the CT scan was correct concerning prevertebral muscle status in 4 out of 20 (20%), whereas open neck exploration was correct in 18 tumors (90%). CONCLUSION: The predictive value of a suspicious CT scan in determining prevertebral muscle invasion is extremely low in this study. Open neck exploration seems to be superior for determining resectability of posterior wall carcinoma.

Adult↗

PubMed1994

Spatial limitation of eye movements during ocular exploration of simple line drawings in neglect syndrome.

The eye movement behaviour of a patient suffering from a right basal ganglia infarction with left-sided neglect but without any visual field defects was investigated during the ocular exploration of simple line drawings. The eye movements were registered by means of an i.r. light technique. Each line drawing consisted of different figural elements located in the centre and both the left and the right half of the picture. In each case, only the contextual connection of the left and right elements in a drawing allowed the spectator to describe the whole scene consistently and to perceive the correct theme of the drawing. The drawings fell into two categories. The cognitive impact of the elements in the drawings' centre was varied by "pointing" to the elements located in the left and right halves with a different strength of connection. When exploring the two types of drawings (weak vs. strong connective elements in the centre) the patient showed a similar eye movement pattern, exploring exclusively the right halves of the drawings. Irrespective of the cognitive impact of the drawing's central elements in "pointing" towards supplementary information in the picture's left half, exploration of this half took place in neither case. A striking difference between the two categories was, however, found concerning the patient's ability to recognize the general context, i.e. to describe the correct theme of the whole drawing. While the patient could not correctly depict any of the scenes from the drawings with weak connective elements in the centre, he was easily capable of properly describing the themes from the group of drawings with strong connective elements, which implies that he must have analysed and perceived the figural elements of both halves of the picture. Different possibilities are discussed to explain the similarity of the patient's exploratory eye movements but discrepancy in his verbal responses when dealing with the two different types of drawings.

Attention↗

PubMed1996

The incidence of positive contralateral inguinal exploration among preschool children--a retrospective and prospective study.

Retrospective and prospective studies were undertaken to evaluate the true incidence of bilateral inguinal involvement in preschool children in an established general pediatric population. Unbiased, anatomically based criteria were established for a "positive" exploration. It was found that bilateral inguinal involvement was highest during the first year of life (68%) and decreased through the advancing years, to just above 50% at 6 years of age. Because a widely patent processus vaginalis may be a precursor of indirect inguinal hernia, contralateral exploration may carry lifelong benefits in those who have the processus vaginalis ligated. Based on the authors' observations, contralateral exploration can be offered to all preschool children, and in selected cases (difficult preoperative preparation, anesthetic high risk, strong family history, etc), even beyond this age. Contralateral exploration is a safe, effective, and cost-wise practice when performed in an appropriate setting.

Child↗

PubMed2002

The management of nonpalpable testis with combined groin exploration and subsequent transinguinal laparoscopy.

PURPOSE: About 20% of all cryptorchid testes are nonpalpable. Although surgical exploration was previously the method of choice for management, laparoscopy from the inferior edge of the umbilicus has been established as a useful method of finding a testis that is nonpalpable. However, conventional subumbilical laparoscopy is unnecessary when the testis or its remnant is located below the internal inguinal ring. We evaluated the efficacy of transinguinal laparoscopy after inguinal exploration for a nonpalpable testis. MATERIALS AND METHODS: While 30 patients each had a unilateral nonpalpable and a contralateral descended palpable testis, 3 had a unilateral nonpalpable and a contralateral undescended palpable testis. When we identified neither a normal testis nor a spermatic cord at exploration of the inguinal canal, we subsequently performed laparoscopic observation through the internal inguinal ring. RESULTS: Of the 30 patients with a unilateral nonpalpable and a contralateral descended testis 8 required transinguinal laparoscopy. However, the procedure was avoided in 22 patients because the testis, its remnant or testicular vessels and vas deferens were detected by inspecting the inguinal region. CONCLUSIONS: Further extended incision into a Pfannenstiel incision was unnecessary in cases of blind ending vas and vessels in the peritoneum with transinguinal laparoscopy. In addition, laparoscopy was avoided in 22 of the 30 children (73.3%) with a unilateral nonpalpable and a contralateral scrotal testis. Our strategy of initial inguinal exploration followed by transinguinal laparoscopy for nonpalpable testis may become a reasonable alternative.

Algorithms↗

PubMed1990

The necessity of contralateral surgical exploration in Wilms tumor with modern noninvasive imaging technique: a reassessment.

Surgical exploration of the contralateral kidney in unilateral Wilms tumor has been the standard of surgical practice. During the last decade advances in noninvasive imaging techniques (ultrasound, computerized tomography and magnetic resonance imaging) have led to more accurate definition of intrarenal pathological conditions. The intuitive question presently is whether contralateral exploration remains mandatory in Wilms tumor patients. We reviewed the records of 52 consecutive children at our institutions who underwent radiological and operative staging of the Wilms tumor from 1979 to 1988. All 48 evaluable patients underwent either preoperative computerized tomography, ultrasound and/or magnetic resonance imaging. Five bilateral Wilms tumors were diagnosed preoperatively and confirmed surgically, whereas extensive operative exploration of the contralateral kidney in the other 43 cases of radiologically diagnosed unilateral disease failed to reveal any contralateral abnormality. Thus, in all patients preoperative radiological investigation was accurate to stage the disease regarding bilaterality. With modern imaging techniques and effective chemotherapy, extensive contralateral renal exploration may no longer be mandatory to manage Wilms tumor.

Child, Preschool↗

PubMed1980

Scrotal explorations negative for malignancy.

We reviewed 74 cases of scrotal exploration via an inguinal approach that were negative for malignancy. Of these explorations 24 (32 per cent) resulted in radical orchiectomy and 14 (19 per cent) resulted in simple orchiectomy. An additional 17 patients (23 per cent) had some other operation in addition to exploration. The most frequent final diagnoses were epididymitis (26 per cent), testicular torsion (18 per cent) and hydrocele (15 per cent). These data demonstrate that scrotal explorations to eliminate the possibility of malignancy result in a high orchiectomy rate for benign disease.

Adolescent↗

PubMed1976

Re-exploration for retroperitoneal lymph node metastases from testis tumors.

Prognosis has been poor for patients with retroperitoneal metastases from non-seminomatous testis tumors that are initially unresectable and persist after chemotherapy and irradiation or those that recur after initial lymphadenectomy. Eleven such patients have had re-explorations at our center and are described herein. In 4 patients only histologically benign teratoma and/or fibrosis was found. Therefore, the presence of a retroperitoneal mass in these circumstances does not necessarily mean that malignant tissue was present. The procedure provided an accurate diagnosis in all patients and permitted the elimination or reduction of subsequent chemotherapy or radiation in 4 patients who had no tumor. In addition, 5 of 7 patients with symptoms caused by bulky masses were improved and 3 patients with unresectable disease had radiopaque markers placed to facilitate subsequent radiotherapy. The operation was often difficult because of retroperitoneal adhesions from previous treatment but there was no significant morbidity and no mortality. Nine patients have survived from 6 months to 4 years and 7 have no evidence of disease. Two patients died of recurrent tumor 2 and 9 months after re-exploration. A good prognosis was indicated if the mass found at re-exploration was completely resectable and contained only histologically benign teratoma and/or fibrous tissue. We believe that re-exploration should be considered for selected patients with testis tumors who have 1) a retroperitoneal mass that appears after initial lymphadenectomy and persists after interval chemotherapy or radiation therapy and 2) retroperitoneal metastases that are initially unresectable and persist after subsequent chemotherapy or radiation therapy.

Adult↗

PubMed1991

Are concomitant surgical procedures acceptable in patients undergoing cervical exploration for primary hyperparathyroidism?

Cervical exploration for primary hyperparathyroidism is an extremely safe procedure with essentially no operative mortality or morbidity and with success rates approaching 98%. These results have encouraged experienced surgeons to perform other surgical procedures concomitantly with cervical exploration with use of the same general anesthetic agent. This retrospective study was performed to assess the safety and efficacy of this practice. At our institution, 117 patients underwent cervical exploration for primary hyperparathyroidism in combination with an additional surgical procedure, including breast (25), biliary (21), gynecologic (19), intra-abdominal (18), and cardiothoracic (6) operations. The mean operative time was 155 minutes, and the mean duration of hospitalization was 7.6 days. Postoperatively, 115 patients (98%) were normocalcemic. Nine complications (mostly minor), which occurred in eight patients, related primarily to the concomitant surgical procedure. No operative mortality occurred. If performed by experienced surgeons in carefully selected patients, cervical exploration for primary hyperparathyroidism in combination with another elective operation is safe and cost-effective.

Adult↗

PubMed2002

Effects of chronic dysthyroidism on activity and exploration.

The aim of the present study was to determine the influence of thyroid function on the activity and exploratory behaviour of male Wistar rats. Dysthyroidism was induced by adding drugs to their drinking water from the ninth day of gestation. This method is not as stressful as daily thyroxine injections or thyroidectomy, and therefore did not affect the analysed behavioural patterns. After weaning, the drugs were administered to the young rats until the end of the experiment. Activity and exploration were measured using the Boissier test, a light-darkness test and an open-field test when they were 77 days old. In order to verify that the animals' motor capacity had not been impaired, a psychomotor battery was used. Chronic hyperthyroidism produced a significant increase in activity, but did not affect exploration. On the other hand, hypothyroidism did not affect activity, but did increase exploration. This increase in exploration was observed in activity-independent behavioural parameters, such as head dipping and glancing.

Animals↗

PubMedDate not supplied

Automation and Robotics for Human Mars Exploration (AROMA).

Automation and Robotics (A&R) systems are a key technology for Mars exploration. All over the world initiatives in this field aim at developing new A&R systems and technologies for planetary surface exploration. From December 2000 to February 2002 Kayser-Threde GmbH, Munich, Germany lead a study called AROMA (Automation and Robotics for Human Mars Exploration) under ESA contract in order to define a reference architecture of A&R elements in support of a human Mars exploration program. One of the goals of this effort is to initiate new developments and to maintain the competitiveness of European industry within this field.

Automation↗

PubMed2001

Enrichment-dependent differences in novelty exploration in rats can be explained by habituation.

In rats, exploratory activity and emotional reactivity towards novel stimuli reflect independent biological functions that are modulated differently by rearing experiences. Environmental enrichment is known to improve performance in exploratory tasks, while having inconsistent effects on emotionality. This study examined the effect of environmental enrichment on the behaviour of rats in two exploratory tasks. Male rats were reared under one of four conditions, differing in social and non-social complexity. At 9 weeks of age, exploration of a novel open field, and exploration of novel objects in the same open field following 24 h habituation, was assessed. Differences in social and non-social complexity of the rearing environment had inconsistent effects on exploration in the novel open field. In contrast, when rats were faced with novel objects in an otherwise familiar environment, exploration habituated faster with increasing stimulus complexity of the non-social environment. The social environment had no effect on this latter test. These findings indicate that environmental enrichment affects exploratory activity primarily through its effect on habituation to novelty. This effect depends on relative stimulus complexity of the rearing environment, but is independent of social factors. The present results further suggest that aversive tasks can obscure the expression of enrichment-dependent differences in habituation to novelty.

Animals↗

PubMed1997

Thoracoscopic evaluation of histologically/cytologically proven or suspected lung cancer: a VATS exploration.

To evaluate the diagnostic value of video-assisted thoracic surgery (VATS), VATS exploration was performed in 135 patients with histologically/cytologically proven or suspected lung cancer. In 31 patients with pulmonary nodules suspected to be lung cancer, VATS exploration was intended to determine their histology by wedge resection. A histological diagnosis was made in all of the patients: 12 lung cancers (38.7%), 12 inflammatory granulomas (38.7%), four hamartomas (12.9%), and three others. VATS exploration (staging) was performed in 116 surgical candidates with documented lung cancer, including the 12 patients diagnosed by VATS wedge resection. Inoperable factors were demonstrated by this procedure in five patients (4.3%): malignant effusion without dissemination in three, malignant effusion with extensive dissemination in one, and extensive dissemination without effusion in one. Furthermore, N2 nodal metastasis at Botallo's ligament was demonstrated by this procedure in two patients, which met the eligibility criteria for a clinical study. Although the documented number of patients was relatively small, VATS exploration obviated the need for painful thoracotomy, selecting better treatment and for evaluating eligibility criteria for prospective clinical trials. The results suggest that this procedure is useful in candidates for lung cancer surgery.

Biopsy, Needle↗

PubMed1999

Success of preoperative imaging and unilateral neck exploration for primary hyperparathyroidism.

The surgical treatment of hyperparathyroidism has become controversial with the recent advent of reliable preoperative imaging modalities. This study examines the efficacy and economy of using preoperative imaging studies to localize the pathology and allow for unilateral neck exploration. From January 1990 to May 1996, a total of 91 patients with primary hyperparathyroidism were treated at Swedish Medical Center in Seattle, WA, by 2 surgeons. Eighty-six nuclear scintigraphy studies were performed, of which 44 were technetium 99m sestamibi (Tc-99m-sestamibi) scans and 42 were thallium 99m technetium (Th-99m-Tc) scans. The overall sensitivity for Tc-99m-sestamibi was 91% (40/44), and that for Th-99m-Tc scans was 81% (34/42). Ultrasound examination revealed a sensitivity of 80% (66/82). There was a statistically significant difference in surgical time between the unilateral and bilateral neck explorations (45 minutes, P < 0.0001). Unilateral neck exploration for hyperparathyroidism has been successful in curing hypercalcemia 93% (85/91) of the time with the use of preoperative imaging studies. Tc-99m-sestamibi is a reliable tool for planning the initial unilateral neck exploration for treatment of primary hyperparathyroidism.

Adenoma↗

PubMed1997

c-fos induction in sensory pathways of rats exploring a novel complex environment: shifts of active thalamic reticular sectors by predominant sensory cues.

In normal rats exploring a novel, complex environment, in comparison to control nonexploring rats, there is induction of the FOS protein, a marker of neuronal activity, in all layers of the striate visual cortex (particularly in the granular and supragranular layers), in the stratum griseum superficiale of the superior colliculus, and in the dorsal lateral geniculate nucleus, as well as in all layers of the whiskers barrel field in the somatosensory cortex. A surprising finding was a selective activation of the visual sector of the thalamic reticular nucleus, in dorsocaudal parts of the nucleus. To the contrary, in visually deprived rats exploring a novel environment which would depend critically on whiskers tactile clues for exploration there was instead a selective activation of the somatic sector in central parts of the thalamic reticular nucleus, in conjunction with activation of cortical whiskers barrel field. From these results it is concluded: (1) Different sensory sectors of the rat thalamic reticular nucleus are activated depending on prevalent sensory channels used in recognition of the environment, suggesting a role of thalamic reticular nucleus in optimizing thalamocortical transmission of essential external cues to guide adequate behaviour. (2) In the awake state, the granular and supragranular layers of the visual and somatosensory cortices are more active when attention is paid to sensory stimuli that are essential for recognition of the environment. (3) The selective induction of c-fos in the visual and somatosensory cortices, and in the stratum griseum superficiale of superior colliculus of rats exploring a novel, complex environment might be related to plastic changes that have been demonstrated in these centres in rats raised in complex environments. These plastic changes are likely to be the result of target late-response genes activated by c-fos.

Animals↗

PubMed2000

[Spermatic cord torsion in the newborn: role of surgical exploration].

UNLABELLED: Torsion of the spermatic cord is frequent in neonates suffering from acute scrotal distress. A retrospective study was carried out to determine the viability and the outcome of testis treated by surgical exploration. PATIENTS AND RESULTS: Surgical exploration of 30 neonates presenting acute scrotal distress found: 18 torsions of the spermatic cord, six intrascrotal bleedings or hematoma due to delivery trauma, five tunica vaginalis inflammations and one ischemia without torsion. The torsion occurred in utero in 16 cases and after birth in two cases. The contralateral uninvolved testis was fixed to the scrotum in all cases. The torsion was extravaginal in 17 cases and intravaginal in one case. In all cases of prenatal torsion, there was total necrosis of the testis. One case of postnatal torsion operated on four hours after the beginning of the torsion was saved. CONCLUSION: Although the viability of the torsioned testis is compromised in cases of prenatal torsion, surgical exploration is necessary to confirm diagnosis and to avoid any contralateral torsion because bilateral torsion exists. Only emergency surgical exploration can save a testis that has undergone post-natal torsion as reported in others series.

Age Factors↗