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At least 73 records · Page 4Linked to original sources

PubMed1998

Laparoscopic common bile duct exploration: practical application.

OBJECTIVE: To evaluate the effectiveness of laparoscopic common bile duct exploration in unselected patients. DESIGN: Consecutive sample. SETTING: Tertiary care general hospital. PATIENTS: Three hundred and two patients with symptomatic cholelithiasis presenting to a single surgeon during a 5-year period. INTERVENTIONS: Laparoscopic cholecystectomy, cholangiography, and common bile duct exploration. MAIN OUTCOME MEASURES: Successful laparoscopic cholecystectomy and common bile duct exploration. RESULTS: Three hundred and two consecutive patients underwent cholecystectomy for symptomatic cholelithiasis; 280 of the procedures were successfully completed laparoscopically. Cholangiography was attempted in 269 patients, was successful in 239, and revealed evidence of choledocholithiasis in 25. Preoperative ultrasonography and liver function tests predicted the presence of common bile duct stones in 24% and 32% of patients, respectively. Seven of the patients with choledocholithiasis presented with biliary colic, 7 with biliary colic and jaundice, 8 with acute cholecystitis (3 with gallbladder perforation), 1 with acute cholecystitis and jaundice, and 2 with gallstone pancreatitis. Four of 5 patients underwent successful transcystic exploration with a biliary Fogarty catheter, 12 of 16 patients underwent successful transcystic choledochoscopy and stone basket extraction, and all 4 attempts at choledochotomy and choledochoscopic stone basket extraction were successful, for a total success rate of 80% with laparoscopic common bile duct exploration. One of the failures was converted to an open procedure, and 4 of the failures had successful postoperative endoscopic retrograde cholangiopancreatography and extraction of stones. CONCLUSIONS: Laparoscopic cholecystectomy and common bile duct exploration is a highly successful procedure for the management of common duct stones in an unselected group of patients. Choledochotomy with choledochoscopy is the preferred method of common bile duct exploration.

Cholangiography↗

PubMed2001

Value of digital exploration for diagnosing injuries to the left side of the diaphragm caused by stab wounds.

HYPOTHESIS: The digital exploration of stab wounds in the left thoracoabdominal region allows the early diagnosis of diaphragmatic lesions. DESIGN: Diagnostic test study. The digital exploration of the diaphragm was compared with laparotomy (the gold standard) and thoracoscopy. SETTING: The study setting was the Hospital Universitario San Vicente de Paúl (Medellín, Colombia). This is a referral trauma center for the general community. PATIENTS: The study included 82 consecutive patients who were admitted to our institution during a 12-month period with injuries caused by stab wounds to the left thoracoabdominal region and who did not have indications for immediate surgery. Digital exploration of the wound was performed by the attending surgeon in the emergency department. If a lesion of the diaphragm was identified, a laparotomy was performed; if no diaphragmatic lesion was found, a diagnostic left thoracoscopy and/or laparotomy was performed. Results of the laparotomy (n = 63) or thoracoscopy (n = 19) were used as the standard of reference for the determination of sensitivity, specificity, and predictive values of digital exploration. INTERVENTION: The integrity of the diaphragm was determined by digital exploration through the stab wound. MAIN OUTCOME MEASURES: Sensitivity, specificity, predictive value, and likelihood ratio were calculated. RESULTS: For the detection of diaphragmatic lesions, digital exploration demonstrated a sensitivity of 96%, a specificity of 83.3%, a positive predictive value of 91%, and a negative predictive value of 93.7%. CONCLUSION: Digital exploration is a reliable method for the detection of injuries to the left side of the diaphragm caused by stab wounds.

Adolescent↗

PubMed2002

Deployment of fingertip forces in tactile exploration.

The purpose of this study was to examine how contact forces normal to the skin surface and shear forces tangential to the skin surface are deployed during tactile exploration of a smooth surface in search of a tactile target. Six naive subjects participated in two experiments. In the first experiment, the subjects were asked to explore a series of unseen smooth plastic surfaces by using the index finger to search for either a raised or recessed target. The raised targets were squares with a height of 280 micro m above the background surface and that varied in side lengths from 0.2 mm to 8.0 mm. A second series of smooth plastic surfaces consisted of small recessed squares (side lengths: 2.0, 3.0, 4.0 and 8.0 mm) that were etched to a depth of 620 micro m. Although made of an identical material, the plastic substrate had a lower coefficient of friction against the skin because only the recessed square had been subjected to the electrolytic etching process. The surfaces were mounted on a six-axes force and torque sensor connected to a laboratory computer. From the three axes of linear force, the computer was able to calculate the instantaneous position of the index finger and the instantaneous tangential force throughout the exploratory period. When exploring for the raised squares, the subjects maintained a relatively constant, average normal force of about 0.49 N with an average exploration speed of 8.6 cm/s. In contrast, all subjects used a significantly higher average normal force (0.64 N) and slightly slower mean exploration speed (7.67 cm/s) when searching for the small recessed squares. This appeared to be an attempt to maximize the amount of skin penetrating the recessed squares to improve the probability of target detection. In a second experiment, subjects were requested to search for an identical set of raised squares but with the fingertip having been coated with sucrose to impede the scanning movement by increasing the friction. Overall, the subjects maintained the same constant normal force that they used on the uncoated surface. However, they increased the tangential force significantly. The similarity of the search strategy employed by all subjects supports the hypothesis that shear forces on the skin provide a significant stimulus to mechanoreceptors in the skin during tactile exploration. Taken together, these data suggest that, in active tactile exploration with the fingertip, the tangential finger speed, the normal contact force, and the tangential shear force are adjusted optimally depending on the surface friction and whether the target is a raised asperity or a recessed indentation.

Adult↗

PubMed1996

Values of ultrasonography, sestamibi scintigraphy, and intraoperative measurement of 1-84 PTH for unilateral neck exploration of primary hyperparathyroidism.

Unilateral neck exploration (UNE) is a controversial approach to the treatment of primary hyperparathyroidism (PHP), and most surgeons favor bilateral neck exploration. The aim of this study was to assess the value of ultrasonography, sestamibi scintigraphy, and intraoperative measurement of urinary cyclic AMP (UcAMP) or 1-84 PTH in 200 patients undergoing unilateral neck exploration under local anesthesia. Conditions for UNE were (1) a presumed solitary adenoma detected by ultrasonography, (2) no thyroid disease, and (3) no family history of PHP or multiple endocrine neoplasia. Patient's consent was obtained for conversion to bilateral exploration according to surgical and biologic findings. Sensitivity of ultrasonography was 92.5%. Sestamibi scintigraphy, performed in 70 patients, was less sensitive than ultrasonography (80%). Persistent PHP was accurately detected by intraoperative measurement of UcAMP or 1-84 PTH in all cases. At follow-up, 96.0% of the patients were cured either after unilateral neck exploration only (90.5%), or after conversion into bilateral exploration. Ultrasonography and intraoperative measurement of 1-84 PTH allow unilateral neck exploration with excellent results in a selected group of patients with PHP.

Adenoma↗

PubMed2004

The roles of humans and robots in exploring the solar system.

Historically, advocates of solar system exploration have disagreed over whether program goals could be entirely satisfied by robotic missions. Scientists tend to argue that robotic exploration is most cost-effective. However, the human space program has a great deal of support in the general public, thereby enabling the scientific element of exploration to be larger than it might be as a stand-alone activity. A comprehensive strategy of exploration needs a strong robotic component complementing and supporting human missions. Robots are needed for precursor missions, for crew support on planetary surfaces, and for probing dangerous environments. Robotic field assistants can provide mobility, access to scientific sites, data acquisition, visualization of the environment, precision operations, sample acquisition and analysis, and expertise to human explorers. As long as space exploration depends on public funds, space exploration must include an appropriate mix of human and robotic activity.

Humans↗

PubMed2005

Early postoperative use of unfractionated heparin or enoxaparin is associated with increased surgical re-exploration for bleeding.

BACKGROUND: A variety of indications (eg, prosthetic heart valves, atrial fibrillation, etc.) exist for the use of unfractionated heparin (UFH) and enoxaparin (ENOX) in the early postoperative period following open-heart surgery. However, the overall postoperative risk for hemorrhage from the use of UFH and ENOX are not known. METHODS: From 1998 to 2001, 2,977 consecutive open-heart or valve surgery patients were retrospectively evaluated. Postoperatively, 2,037 received no UFH or ENOX, 579 received intravenous UFH, and 361 received ENOX. Baseline characteristics were collected, patients who required surgical re-exploration for postoperative bleeding and time between surgery and re-exploration were followed-up. RESULTS: Average patient ages were 64 +/- 13, 65 +/- 12, and 68 +/- 10 years receiving none, UFH (p < 0.01 vs none), and ENOX (p < 0.01 vs none; p < 0.01 vs UFH), respectively. Rates of surgical re-exploration were 2.7% for none, 7.8% for UFH, and 8.9% for ENOX (vs none, adjusted hazard ratio = 2.8; p < 0.001 for UFH; hazard ratio = 3.3; p < 0.001 for ENOX). Males were also at higher risk for re-exploration (hazard ratio = 1.4; p = 0.07). For those requiring re-exploration, the interval between surgery and first re-exploration was prolonged (> 4 days) among those receiving ENOX (37.5%, odds ratio = 36.7; p = 0.001) and UFH (20.0%, odds ratio = 14.7; p = 0.01) compared with none (1.8%). Prolonged times with ENOX had a greater proportion of prolonged times than UFH (odds ratio = 2.5; p = 0.09). CONCLUSIONS: Early postoperative use of ENOX and UFH is associated with a significant increase in re-exploration for postoperative bleeding, often at a significantly delayed time period after the initial surgery. This delay was especially common with ENOX suggesting the need for prospective studies.

Aged↗

PubMed2004

Prospective evaluation of sestamibi scan, ultrasonography, and rapid PTH to predict the success of limited exploration for sporadic primary hyperparathyroidism.

BACKGROUND: The aim of this study was to determine the ability of localizing studies and rapid intraoperative parathyroid hormone (PTH) to predict the success of a limited approach in patients who then underwent bilateral exploration. METHODS: Preoperative sestamibi-iodine subtraction scan and neck ultrasonography (US) were used to direct a focal (1-gland) and unilateral (1-sided) parathyroid exploration by using rapid intraoperative PTH determinations in 350 patients with sporadic primary hyperparathyroidism. Regardless of the findings, the contralateral side was then explored. RESULTS: A single gland was predicted by sestamibi in 290 patients (83%), US in 298 patients (85%), and concordance of both in 205 patients (59%). Unilateral parathyroid exploration, directed by these studies, would correctly identify single-gland disease in only 68%, 74%, and 79%, respectively. The addition of intraoperative PTH would increase the success rate to 73%, 77%, and 82%, respectively. The finding of 2 normal or 2 abnormal glands on 1 side would force bilateral exploration, and additional unsuspected pathology was found in 13%, 13%, and 9%, respectively. This failure rate would increase to 21%, 18%, and 15%, respectively, if the analysis assumed a focal rather than unilateral approach to the initial exploration. CONCLUSIONS: Even in patients with concordant sestamibi and US scans, and an appropriate PTH drop, additional abnormal parathyroid glands were found on complete exploration in 15%. A bilateral approach offers the best opportunity for the long-term cure of primary hyperparathyroidism.

Adenoma↗

PubMed2005

Idiosyncratic initiation of saccadic face exploration in humans.

Visual processing and subsequent action are limited by the effectiveness of eye movement control: where the eyes fixate determines what part of the visual environment is seen in detail. Visual exploration consists of stereotypical sequences of saccadic eye movements which are known to depend upon both external factors, such as visual stimulus features, and internal cognition-related factors, such as attention and memory. However, how these two factors are balanced is unknown. One determinant might be the familiarity or ecological importance of the visual stimulus being explored. Recordings of saccades for human face stimuli revealed that their exploration was subject to strong individual biases for the initial saccade direction: subjects tended to look first to one particular side. We attribute this to internal factors. In contrast, exploration of landscapes, fractals or inverted faces showed no significant direction bias for initial saccades, suggesting more externally driven exploration patterns. Thus the balance between external and internal factors in scene exploration depends on stimulus type. An analysis of saccade latencies suggested that this individual preference for first saccade direction during face exploration leads to higher effectiveness through automation. The findings have implications for the understanding of both normal and abnormal eye movements.

Adolescent↗

PubMed2001

Laparoscopic exploration for the clinically undetected hernia in infancy and childhood.

BACKGROUND: Routine contralateral groin exploration in infants and children with a clinically detected inguinal hernia is the subject of much debate. The detection of a patent processus vaginalis by transinguinal laparoscopy has proven advantageous. However, controversy remains regarding the true incidence of a contralateral patent processus vaginalis as well as which of these will actually develop into a clinically apparent hernia. METHODS: From January 1997 through December 1999, 358 infants and children (aged 1 to 157 months, mean 32) were treated in the three University of Oklahoma teaching hospitals in Tulsa, Oklahoma, for inguinal hernia. The findings at laparoscopic exploration of the contralateral side were recorded to determine the incidence of contralateral patency as it relates to a child's age, gender, and side of the initial clinical diagnosis. RESULTS: The overall incidence of a patent processus vaginalis on contralateral examination was 33% (117 of 358). All patent processus vaginalis were repaired. Bilateral inguinal hernia was significantly more common in younger patients (present in 50% if less than 1 year, 45% if less than 2 years, 37% if less than 5 years, and 15% if greater than 5 years of age; P <0.05). In boys, the incidence was 49%, 45%, and 32% in those under 1 year of age, under 2 years of age, and in total, respectively. In girls, the incidence was 59%, 50%, and 37% in those under 1 year of age, under 2 years of age, and in total, respectively. The side of the clinically detected hernia did not influence the laparoscopic findings of a contralateral hernia with 30% (50 of 169) positive findings on left inguinal exploration versus 31% (28 of 90) positive findings on right inguinal exploration. CONCLUSIONS: The high incidence of a contralateral patent processus vaginalis warrants routine laparoscopic exploration in infants and children undergoing unilateral inguinal hernia repair, especially those less than 5 years of age. The use of transinguinal laparoscopic explorations avoids unnecessary open exploration in 66% of infants and children undergoing inguinal hernia repair.

Age Factors↗

PubMed2002

Early repeated exploration after laparoscopic urologic surgery: comparison of clinical, radiologic, and surgical findings.

OBJECTIVES: To correlate the clinical scenarios and radiographic findings with the operative findings in patients who underwent repeated exploration to define a management strategy. Postoperative complications after laparoscopy may cause diagnostic challenges because of atypical presentation. METHODS: We retrospectively reviewed the records from 1226 urologic laparoscopic procedures between July 1993 and July 2000. We compared the clinical, radiologic, and surgical findings of patients who underwent repeated exploration within the first month after laparoscopy. RESULTS: During the study period, 9 patients (0.7%) were taken back to the operating room for repeated exploration. The median time for the appearance of symptoms was the second postoperative day. Eight patients were evaluated by computed tomography (CT) and one by both renal Doppler ultrasonography and MAG-3 renal perfusion scan. Repeated operations were laparoscopic in 4 and open in 5 patients. In all the patients evaluated by CT scan, the radiologic findings were consistent with the surgical findings. In the patients who underwent diagnostic laparoscopy because of the severity of clinical findings, despite negative CT findings, no abnormality was discovered at exploration. In 1 patient who was not evaluated by CT, duodenal perforation was detected at exploration. CONCLUSIONS: Clinical findings may not be sufficient for the decision of repeated operation for patients acutely ill after laparoscopy. CT findings correlated well with the findings at exploration. In cases in which no abnormality is detected by CT, it appears reasonable to withhold surgical exploration unless the clinical situation deteriorates.

Adult↗

PubMed2003

Neonatal cholinergic lesions and development of exploration upon administration of the GABAa receptor agonist muscimol in preweaning rats.

Neonatal rats were administered 192 IgG-saporin (192 IgG-Sap), a selective cholinergic immunotoxin, on postnatal day (PND) 7. Behavioural responsiveness to muscimol, a GABAa receptor agonist, was then assessed using locomotor activity and object exploration tests on PND 18. In Experiment 1, 192 IgG-Sap-lesioned and control rats were injected with the GABAa agonist, muscimol, on PND 18 and tested in a standard open field test. Muscimol reduced rearing responses in both control and 192 IgG-Sap-lesioned animals whereas reduced wall-rearing responses occurred in control animals only. 192 IgG-Sap also reduced rearing and wall-rearing responses. In Experiment 2, muscimol effects were evaluated on PND 18 in a spatial open field test in which object exploration in addition to locomotion and rearing responses was assessed. Neonatal cholinergic lesion per se increased locomotion during object exploration while decreasing time spent exploring objects. Depressant effects of muscimol on object exploration were also evident. As a whole, these data provide evidence for (i) basal forebrain (BF) cholinergic control on locomotor activity and object exploration and (ii) GABAa-mediated regulation of selective behavioural patterns associated with locomotion and exploration in weaning rats. Neonatal cholinergic lesions, however, do not appear to alter reactivity to GABAergic agonists in juvenile rats.

Animals↗

PubMed2002

Comparison of endoscopic sphincterotomy and laparoscopic exploration of the common bile duct.

BACKGROUND: Laparoscopic exploration of the common bile duct is becoming more popular, although endoscopic sphincterotomy remains the usual treatment for bile duct stones. However, loss of the biliary sphincter causes permanent duodenobiliary reflux, and recurrent stone disease and biliary neoplasia may be a consequence. METHODS: A systematic literature review was conducted to compare laparoscopic exploration with endoscopic sphincterotomy. A text word search of the Medline, Pubmed and Cochrane databases, and a manual search of the citations from these references, was used. RESULTS: Endoscopic sphincterotomy is associated with a median (range) mortality rate of 1 (0-6) per cent, compared with 1 (0-5) per cent for laparoscopic bile duct exploration. The median (range) rate of pancreatitis following endoscopic sphincterotomy is 3 (1-19) per cent; this is a rare complication after laparoscopic duct exploration. The combined morbidity rate for laparoscopic cholecystectomy and endoscopic sphincterotomy is 13 (3-16) per cent, which is greater than 8 (2-17) per cent for laparoscopic bile duct exploration. Randomized trials are few and contain relatively small numbers of patients. They show little overall difference in rates of duct clearance, but a higher mortality rate and number of hospital admissions are noted for endoscopic sphincterotomy compared with laparoscopic bile duct exploration. Endoscopic sphincterotomy is associated with recurrent stone formation (up to 16 per cent) with associated cholangitis. It is also associated with bacterobilia and chronic mucosal inflammation. The late development of bile duct cancer has been reported in up to 2 per cent of patients. CONCLUSION: Laparoscopic exploration of the common bile duct may be a better way of removing stones than endoscopic sphincterotomy plus laparoscopic cholecystectomy. :

Aged↗

PubMed2000

Effects of infant and caregiving conditions on an infant's focused exploration of toys.

An infant's exploration of toys, in the context of the mother's regulating actions, is a setting for cognitive and social development. The aim of this study was to examine the contribution of infant and caregiving conditions to the quantity of focused exploration of toys for 8-month-old infants. Infant biological conditions were gender and birth weight, including a range of both prematurely and term-born infants. The infant behavioural condition was responsiveness to care. Caregiving conditions included mother's education, the supportive, stimulating and sustaining quality of the home environment, and the attention-directing and -supporting behaviour of the mother during play. The direct and indirect effects of these conditions on focused toy exploration were modelled using multiple regression. The sample of 79 mother-infant dyads included 43 full-term infants and 36 premature infants. The mother's attention-directing behaviour was a significant negative predictor of focused toy exploration. Infant birth weight did not have a significant direct effect on focused toy exploration. Birth weight did not interact significantly with responsiveness to care or with any of the caregiving environment conditions to affect focused toy exploration. Further study of infant responses to the mother's attention-regulating and emotion-regulating behaviour during play is recommended to better understand how the caregiving environment supports or thwarts focused toy exploration.

Adult↗

PubMed1998

Management of the orbital rim and floor in zygoma and midface fractures: criteria for selective exploration.

The management of zygomaticomaxillary and midface fractures has been revolutionized in the past decade as a result of improved surgical access, rigid plating systems, and high-resolution computed tomography. Previously, virtually all midface fractures underwent mandatory orbital exploration to aid in reduction and stabilization. This article emphasizes the importance of reducing and fixating the facial buttresses involved in zygomatic complex fractures, and recommends orbital exploration on a selective basis. Criteria are given to decide which patients require orbital rim and floor exploration. If a patient's fracture does not meet these criteria, the fracture is managed by exposing, reducing, and stabilizing the major facial buttresses involved without performing an orbital exploration. Ninety-seven patients with zygomatic complex fractures were examined and treated with selective orbital rim and floor explorations. Most patients could be managed without the need for orbital exploration, and all were felt to have good fracture reduction and stability. We feel the selection criteria reliably identify patients who do require an orbital exploration and allow the treating surgeon to direct surgical treatment to the site of injury.

Facial Bones↗

PubMedDate not supplied

A model and framework for visualization exploration.

Visualization exploration is the process of extracting insight from data via interaction with visual depictions of that data. Visualization exploration is more than presentation; the interaction with both the data and its depiction is as important as the data and depiction itself. Significant visualization research has focused on the generation of visualizations (the depiction); less effort has focused on the exploratory aspects of visualization (the process). However, without formal models of the process, visualization exploration sessions cannot be fully utilized to assist users and system designers. Toward this end, we introduce the P-Set Model of Visualization Exploration for describing this process and a framework to encapsulate, share, and analyze visual explorations. In addition, systems utilizing the model and framework are more efficient as redundant exploration is avoided. Several examples drawn from visualization applications demonstrate these benefits. Taken together, the model and framework provide an effective means to exploit the information within the visual exploration process.

Algorithms↗

PubMed2006

Habitat exploration and use in dispersing juvenile flying squirrels.

1. Variation in behaviours involved in habitat selection is important for several evolutionary and ecological processes. For example, habitat use during dispersal may differ from breeding habitat use, and for dispersers the scale of habitat familiarity is determined by exploratory behaviour. We studied habitat use and exploration of 56 radio-collared juvenile flying squirrels Pteromys volans L. within natal home range and during dispersal, and compared habitat use between juveniles and 37 adults within breeding home range. 2. Before dispersal, young flying squirrels actively moved around the natal site. Surprisingly, long-distance dispersers explored less than short-distance dispersers, but philopatric individuals explored similar distances as dispersers. Females explored less than males, although females are the more dispersive sex in flying squirrels. 3. For most of the individuals the settlement area was unfamiliar due to long dispersal distance. Consequently, direction and distance of exploration were not very strong predictors of settlement location. However, individuals familiar with the settlement area concentrated exploration to that area. Exploration did not correlate with short-term survival. 4. Dispersers preferred breeding habitat while dispersing, but were found more often in matrix habitat than juveniles within natal, or adults within breeding, home ranges. 5. We conclude that familiarity does not determine settlement as much as, for example, availability of the habitat for flying squirrels. Based on our results, it also seems clear that data on adult habitat use are not enough to predict habitat use of dispersing individuals. In addition, our results support the recent view that short- and long-distance dispersers may need to be analysed separately in ecological and evolutionary analyses.

Aging↗

PubMed1991

Parathyroid exploration. A review of 125 cases.

Cervical exploration was performed in 106 patients with primary hyperparathyroidism and in 19 patients with chronic renal failure. Initial exploration for primary hyperparathyroidism was successful in 97% of the cases. Single adenomas were found in 84, double adenomas in six, and multiple-gland hyperplasia in 12 patients. Two of the four patients in whom cervical exploration failed were ultimately given the diagnosis of benign familial hypocalciuric hypercalcemia. Thirteen adenomas were ectopic. Preoperative thallium-technetium scans and ultrasound correctly localized only 63% of the adenomas. Only 45% of the ectopic adenomas were correctly localized. All four glands should be examined at initial exploration. Because of the occurrence of double adenomas, contralateral exploration is always indicated regardless of whether an enlarged gland and a normal one are found on the first side. All enlarged parathyroids should be removed when dealing with single or multiple adenomas; subtotal parathyroidectomy (3 1/2 glands) should be performed in multiple-gland hyperplasia. Frozen section confirmation of excised parathyroid tissue is essential. If exploration is unsuccessful, ectopic locations such as the retroesophageal areas, thymus, anterior and posterior mediastinum, carotid sheath, and thyroid lobe must be searched carefully. Preoperative localization studies are not as reliable as an experience parathyroid surgeon.

Adenoma↗

PubMed1996

Evaluation of prevertebral muscle invasion by squamous cell carcinoma. Can computed tomography replace open neck exploration?

OBJECTIVE: To compare computed tomography (CT) with open neck exploration in determining prevertebral invasion by squamous cell carcinoma of the oropharynx or hypopharynx. DESIGN: Retrospective analysis using the findings at open neck exploration and results of histopathologic studies as the criterion standards. SETTING: Tertiary care referral center. PATIENTS: Twenty-nine of 40 patients with advanced squamous cell carcinoma of the oropharynx or hypopharynx treated between January 1, 1986, and December 31, 1994, were selected for analysis based on CT findings of posterolateral extension of the primary tumor placing the prevertebral muscle (PVM) at risk. All study patients had no previous therapy and underwent neck exploration to determine resectability. RESULTS: Overall accuracy of CT in predicting PVM status was 55.2%. The sensitivity of preoperative CT for PVM invasion was 50%; the specificity was 61%. Using an estimate of 21% for the prevalence of PVM invasion, the predictive value of a positive CT scan was 0.254 and the predictive value of a negative CT scan was 0.821. Open neck exploration correctly predicted PVM status in all cases. CONCLUSIONS: Open neck exploration is superior to CT to evaluate possible PVM invasion by squamous cell carcinoma of the oropharynx or hypopharynx. The predictive value of a negative CT scan for PVM invasion is high, so it may be useful in treatment planning. Patients with advanced squamous cell carcinoma of the oropharynx or hypopharynx at risk for PVM invasion who are otherwise surgical candidates should be considered for open neck exploration to determine resectability most accurately.

Adult↗