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Quan-Yang Duh

Publications and source records attributed to Quan-Yang Duh.

At least 37 records · Page 2Linked to original sources
PubMed2005

Diagnostic and prognostic value of angiogenesis-modulating genes in malignant thyroid neoplasms.

BACKGROUND: Angiogenesis is an essential biologic event in the pathogenesis of human malignancies. We postulated that expression analysis of genes that modulate angiogenesis would identify differentially expressed genes that would help to distinguish benign from malignant thyroid neoplasms and serve as markers of aggressive differentiated thyroid cancer. METHODS: A complementary DNA (cDNA) array with 96 genes that modulate angiogenesis was used to identify differentially expressed genes (2-fold higher or lower) in malignant versus benign thyroid neoplasms. Real-time quantitative polymerase chain reaction was used to confirm cDNA array expression data in 123 patients (4 normal thyroid, 26 hyperplastic nodules, 27 follicular adenomas, 23 follicular cancers, 18 follicular variant of papillary cancers, 25 papillary cancers). RESULTS: Twenty-two genes were upregulated in malignant thyroid neoplasms by cDNA array analysis, but only 13 genes had higher messenger RNA (mRNA) expression levels in malignant than in benign thyroid neoplasms by real-time quantitative polymerase chain reaction (P < or = .04). Of the 13 differentially expressed genes, the combined use of angiopoietin 2 (ANGPT2) and tissue inhibitor of metalloproteinase 1 (TIMP1) mRNA expression levels was best for distinguishing malignant from benign thyroid neoplasms, with a sensitivity of 90%, specificity of 85%, positive predictive value of 75%, and negative predictive value of 94%. Epidermal growth factor receptor and ephrin B2 mRNA expression was elevated in higher TNM stage neoplasms and in patients with high-risk AMES (Age, distant Metastasis, Extrathyroidal invasion, and tumor Size) differentiated thyroid cancers (P < or = .005). CONCLUSIONS: Angiopoietin 2 and tissue inhibitor of metalloproteinase 1 are diagnostic markers of malignant thyroid nodules and could improve the diagnostic accuracy of FNA biopsy. Epidermal growth factor receptor and ephrin B2 are markers of aggressive differentiated thyroid cancer.

Adenocarcinoma, Follicular↗
PubMed2005

Valproic acid inhibits growth, induces apoptosis, and modulates apoptosis-regulatory and differentiation gene expression in human thyroid cancer cells.

BACKGROUND: Among the most promising new therapies for thyroid cancer are the histone deacetylase inhibitors. Valproic acid (VA) is an anticonvulsant that inhibits histone deacetylase activity at nontoxic concentrations. We hypothesized that VA would have antineoplastic effects on human thyroid cancer cells. METHODS: We treated 1 papillary and 3 follicular thyroid cancer cell lines with VA (0.5-2 mmol/L) for 24 to 72 hours. Cell proliferation was measured with a cell proliferation assay kit. Annexin V-fluorescein isothiocyanate was used to quantitate cells that were undergoing apoptosis. Quantitative polymerase chain reaction was used to measure expression of apoptosis-regulatory and differentiation genes. RESULTS: VA inhibited growth in all cell lines by 26% to 59% at 48 hours and up to 77% at 72 hours. Nineteen percent to 30% of VA-treated cells underwent apoptosis, compared with 4% to 8% of the control cells. Expression of pro survival genes bcl-2 and bcl-xl was down-regulated by 10% to 60%; expression of the proapoptosis gene bax was up-regulated by 23% to 85%. Sodium-iodide symporter and thyroglobulin messenger RNA expression were up-regulated by 93% to 370% in follicular cell lines but remained unchanged in the papillary cell line. CONCLUSION: VA inhibits growth, induces apoptosis, and modulates apoptosis-regulatory and differentiation gene expression in thyroid cancer cells. These findings suggest that VA may be useful clinically for patients with thyroid cancers of follicular cell origin.

Adenocarcinoma, Follicular↗
PubMed2005

Use of the electrothermal vessel sealing system versus standard vessel ligation in thyroidectomy.

OBJECTIVE: The electrothermal vessel sealing system (LigaSure) facilitates operative haemostasis by fusing blood vessel walls to form a collagen seal. The LigaSure is currently used in a variety of gastrointestinal, gynaecological and urological operations. We report our experience with LigaSure for thyroidectomy to test the hypothesis that it reduces operating time without increasing complications compared with standard vessel ligation. METHODS: This non-randomized, retrospective review included 234 consecutive patients who underwent thyroidectomy by one surgeon. Standard vessel ligation was used in 99 patients between 1997 and 2000, and the LigaSure was used in 135 patients between 2001 and 2003. The following data were collected: patient demographics, thyroid pathology, type of operation (total thyroidectomy vs lobectomy), operating time, complications (transient or permanent hypocalcaemia, <or=8 mg/dL), recurrent or superior laryngeal nerve injury, neck haematoma, wound complications, prolonged intubation), incision length and hospital stay. RESULTS: The two groups had similar demographics, thyroid pathology, types of operations and complication rates. The LigaSure group had lower operating times and incision lengths. CONCLUSION: We found that the LigaSure was as safe as standard vessel ligation for thyroidectomy, with the benefit of reduced operating time. A future prospective study has been designed.

Adult↗
PubMed2005

Laparoscopic appreciation of the adrenal artery: fact or fiction?

BACKGROUND: It is well accepted that identification and control of the adrenal vein is a critical step in laparoscopic adrenalectomy. The surgical and anatomic literature propagates the notion of a dominant or multiple dominant adrenal arteries that should likewise be controlled during surgical extirpation. MATERIALS AND METHODS: We assessed the frequency of adrenal-artery identification and the need for formal ligation in an extensive series of laparoscopic adrenalectomies. RESULTS: In our experience, even using a magnified laparoscopic view, we found it possible to identify and necessary to formally ligate an adrenal artery in only 3 of 265 cases (1.1%). Further, in this series, only the inferior adrenal artery was ever seen definitively to require formal clip ligation, while a discrete middle or superior adrenal artery was almost never seen, and the vasculature in these areas could be controlled with electrocautery or ultrasonic energy alone during routine dissection. CONCLUSIONS: The need to search for and ligate the arterial supply during laparoscopic adrenalectomy is not as clinically significant as once thought, and formal control appears unnecessary unless the vessels are serendipitously encountered during the routine dissection.

Adrenal Glands↗
PubMed2005

Troglitazone, the peroxisome proliferator-activated receptor-gamma agonist, induces antiproliferation and redifferentiation in human thyroid cancer cell lines.

Troglitazone is a potent agonist for the peroxisome proliferator-activated receptor-gamma (PPARgamma) that is a ligand-activated transcription factor regulating cell differentiation and growth. PPARgamma may play a role in thyroid carcinogenesis since PAX8-PPARgamma1 chromosomal translocations are commonly found in follicular thyroid cancers. We investigated the antiproliferative and redifferentiation effects of troglitazone in 6 human thyroid cancer cell lines: TPC-1 (papillary), FTC-133, FTC-236, FTC-238 (follicular), XTC-1 (Hürthle cell), and ARO82-1 (anaplastic) cell lines. PPARgamma was expressed variably in these cell lines. FTC-236 and FTC-238 had a rearranged chromosome at 3p25, possibly implicating the involvement of the PPARgamma encoding gene whereas the other cell lines did not. Troglitazone significantly inhibited cell growth by cell cycle arrest and apoptotic cell death. PPARgamma overexpression did not appear to be a prerequisite for a response to treatment with troglitazone. Troglitazone also downregulated surface expression of CD97, a novel dedifferentiation marker, in FTC-133 cells and upregulated sodium iodide symporter (NIS) mRNA in TPC-1 and FTC-133 cells. Our investigations document that human thyroid cancer cell lines commonly express PPARgamma, but chromosomal translocations involving PPARgamma are uncommon. Troglitazone, a PPARgamma agonist, induced antiproliferation and redifferentiation in thyroid cancer cell lines. PPARgamma agonists may therefore be effective therapeutic agents for the treatment of patients with thyroid cancer that fails to respond to traditional treatments.

Adenocarcinoma, Follicular↗
PubMed2005

Should total thyroidectomy become the preferred procedure for surgical management of Graves' disease?

This study aims to evaluate our institution's experience with thyroidectomy for Graves' disease, with an emphasis on indications and long-term outcomes. The study cohort consisted of 103 patients (mean age 34.3 [+/-13.9] years), who underwent thyroidectomy for Graves' disease between 1991 and 2002. Clinical and follow-up data were obtained by retrospective review of medical records and by contacting treating physicians or patients. The most common surgical indications were patient preference (26%), cold nodule (24%), eye symptoms (20%), large goiter size (18%), allergy to antithyroidal medications (15%), and age younger than 16 years (14%). Thyroidectomies performed included 45 (total or near-total), 57 subtotal, and 1 lobectomy. Transient complications included hypocalcemia in 42 patients, and recurrent laryngeal nerve palsy in 5 patients. There was no difference in the frequency of hypocalcemia in patients undergoing total or subtotal resections. One patient developed permanent hypocalcemia and 2 permanent recurrent laryngeal nerve (RLN) injury. Only 3 patients who underwent subtotal resections remain off thyroxine and 2 developed recurrent hyperthyroidism approximately 17 and 54 months after surgery. Subtotal thyroidectomy is associated with a high rate of hypothyroidism and large remnants have potential for recurrence. Total or near-total thyroidectomy obviates these disadvantages and can be performed without increased complication rates, thus appearing to be the preferred extent of thyroidectomy for Graves' disease.

Adolescent↗
PubMed2005

Variable expression of coxsackie-adenovirus receptor in thyroid tumors: implications for adenoviral gene therapy.

Adenoviral gene therapy represents a novel approach for the treatment of aggressive thyroid carcinomas. Both coxsackie-adenovirus receptor (CAR) and integrins have been shown to be the major determinants for adenoviral infectivity in many types of cancer cells, yet conflicting results have been reported. In this report we examine these factors mediating adenoviral infection in thyroid cells and to evaluate CAR expression in various types of thyroid cancer. We found that neither expression levels of CAR nor integrins are solely predictive of adenoviral infectivity in thyroid cells. However, the absence of CAR was associated with poor adenoviral infectivity in immortalized rat FRTL-5 cells. Moreover, preincubation with alpha-CAR antibody decreased infectivity in FTC 238 cells, a human thyroid tumor line. These results indicate that CAR does play a role in adenoviral infection of thyroid cells. Immunohistochemical analysis revealed that CAR is expressed at the cell surface in the majority of malignant thyroid tumors. We further show that adenoviral infectivity in some thyroid cancer cells can be improved by poly-L-lysine. Our study warrants a functional method to evaluate adenoviral infectivity should be developed and instituted prior to clinical trials of adenoviral gene therapy in patients with advanced thyroid cancer.

Adenoviridae↗
PubMed2005

ECM1 and TMPRSS4 are diagnostic markers of malignant thyroid neoplasms and improve the accuracy of fine needle aspiration biopsy.

OBJECTIVE: The objective of this study was to determine whether genes that regulate cellular invasion and metastasis are differentially expressed and could serve as diagnostic markers of malignant thyroid nodules. SUMMARY AND BACKGROUND DATA: Patients whose thyroid nodules have indeterminate or suspicious cytologic features on fine needle aspiration (FNA) biopsy require thyroidectomy because of a 20% to 30% risk of thyroid cancer. Cell invasion and metastasis is a hallmark of malignant phenotype; therefore, genes that regulate these processes might be differentially expressed and could serve as diagnostic markers of malignancy. METHODS: Differentially expressed genes (2-fold higher or lower) in malignant versus benign thyroid neoplasms were identified by extracellular matrix and adhesion molecule cDNA array analysis and confirmed by real-time quantitative polymerase chain reaction (PCR). The area under the receiver operating characteristic (AUC) curve was calculated to determine diagnostic accuracy of gene expression level cutoffs established by logistic regression analysis. RESULTS: By cDNA array analysis, ADAMTS8, ECM1, MMP8, PLAU, SELP, and TMPRSS4 were upregulated, and by quantitative PCR, ECM1, SELP, and TMPRSS4 mRNA expression was higher in malignant (n = 57) than in benign (n = 38) thyroid neoplasms (P< 0.002). ECM1 and TMPRSS4 mRNA expression levels were independent predictors of a malignant thyroid neoplasm (P < 0.003). The AUC was 0.956 for ECM1 and 0.926 for TMPRSS4. Combining both markers improved their diagnostic use (AUC 0.985; sensitivity, 91.7%; specificity, 89.8%; positive predictive value, 85.7%; negative predictive value, 82.8%). ECM1 and TMPRSS4 expression analysis improved the diagnostic accuracy of FNA biopsy in 35 of 38 indeterminate or suspicious results. The level of ECM1 mRNA expression was higher in TNM stage I differentiated thyroid cancers than in stage II and III tumors (P < or = 0.031). CONCLUSIONS: ECM1 and TMPRSS4 are excellent diagnostic markers of malignant thyroid nodules and may be used to improve the diagnostic accuracy of FNA biopsy. ECM1 is also a marker of the extent of disease in differentiated thyroid cancers.

Biomarkers, Tumor↗
PubMed2004

Prognostic indications for Hürthle cell cancer.

Hürthle cell carcinoma (HCC) has been reported to have variable clinical behavior. The objective of this study was to determine the important prognostic factors in patients with HCC. It was a retrospective investigation of 33 patients with HCC treated in our institution from 1976 to 2002. The average age of our 33 patients with HCC was 55.2 years (range 20-82 years; 23 women, 10 men). Fifteen patients (45.5%) presented with a T2 tumor, 7 (21.2%) with a T3 tumor, and 8 (24.2%) with a T4 tumor; the tumor stage was unknown in three patients. Coexisting papillary carcinoma occurred in six patients (18%), 9% of whom presented with metastatic disease. Twelve patients (36.4%) had metastases, four of whom (12.2%) had persistent HCC, and 8 (24.2%) developed recurrent HCC (range 1-9 years). Eight of these twelve patients (66.7%) died from the HCC. The average follow-up time was 5.5 years (range 1-16 years). Altogether, 3 of 23 women and 5 of 10 men died from their HCC ( p < 0.05). Of the 22 patients with T2-T3 tumors, 5 (22.7%) developed metastases and 1 patient died; 5 of 8 patients (62.5%) with T4 tumors developed metastases and died ( p < 0.01). Patients who were treated by less than total thyroidectomy had a worse prognosis by univariate analysis ( p < 0.01) but not by multivariate analysis. Survival time for patients with persistent disease was shorter than for those with recurrent disease ( p < 0.05). Multivariate analysis, however, revealed no difference for extent of operation or those with persistent and recurrent disease. The cause-specific survivals were 74% and 49% at 5 and 10 years, respectively. Disease-free survivals were 65.0% and 40.5% at 5 and 10 years, respectively. Our findings show that gender and stage of disease influence the prognosis of patients with HCC.

Adenoma, Oxyphilic↗
PubMed2004

Follicular thyroid carcinoma: histology and prognosis.

BACKGROUND: Follicular thyroid carcinoma (FTC) is the second most common thyroid malignancy after papillary thyroid carcinoma. The authors studied the clinical course of 132 patients with FTC to determine whether there was a direct relation between the histologic degree of invasion, tumor recurrence, and patient survival. METHODS: The 132 patients in the study population underwent 182 thyroid carcinoma-related operations, and their mean follow-up was 7.5 years (median:,6 years; range, 0-39 years). The following criteria were used to define malignant follicular neoplasms: 1) minimally invasive, tumor invasion through the entire thickness of the tumor capsule; 2) moderately invasive, tumor with angioinvasion (with or without capsular invasion); and 3) widely invasive, broad area or areas of transcapsular invasion of thyroid and extrathyroidal tissue. Forty-five of 119 patients (37.8%) presented with minimally invasive FTC (capsular invasion only), 50 patients (42%) presented with moderately invasive FTC (angioinvasion with or without capsular invasion), and 24 patients (20%) presented with widely invasive FTC. At presentation, 12 patients (9%) had distant metastases, and 8 patients (6%) had lymph node metastases. RESULTS: Excluding 12 patients who presented with distant metastases, 21 patients (16%) developed recurrent metastases 6 months after their initial treatment. Among 45 patients with capsular invasion only, 6 patients (13%) developed recurrent or persistent disease, and 5 patients (11%) died. Of the 50 patients who had angioinvasion with or without capsular invasion, 10 patients (20%) developed recurrent or persistent disease, and 7 patients (14%) died. Patients who had angioinvasion with or without capsular invasion had a less favorable prognosis compared with patients who had capsular invasion only (P < 0.0001). Among patients who had widely invasive FTC, 9 of 24 patients (38%) developed recurrent disease, and 8 patients (33%) died; in addition, 7 of the other 24 patients (29%) had persistent disease and died. The overall death rate for patients with widely invasive FTC was 62%. Patients with persistent disease had a poorer prognosis compared with patients who had recurrent disease (P < 0.0001). Twenty-eight patients (21%) in the entire group died of FTC. CONCLUSIONS: In the current retrospective investigation, the authors demonstrate that patients with minimally invasive FTC (capsular invasion only) had a slightly better survival rate at 5 years (98%) compared with patients who had angioinvasion with or without capsular invasion (80%) and had better survival compared with patients who had widely invasive FTC (38%). Other (but not all) reports in the literature support the findings that FTC with angioinvasion is more aggressive than FTC with only capsular invasion yet is less aggressive than widely invasive FTC. The authors conclude that FTC no longer should be classified as either minimally invasive or widely invasive; rather, they recommend classifying FTC as minimally invasive, moderately invasive, or widely invasive, because prognosis varies according to these groupings.

Adenocarcinoma, Follicular↗
PubMed2004

Complication of thyroidectomy in patients with radiation-induced thyroid neoplasms.

HYPOTHESIS: The complication rate for thyroidectomy is the same in patients with and without a history of radiation exposure. DESIGN: Retrospective medical record review of 171 consecutive patients who had a previous history of radiation treatment and had undergone a thyroid operation from 1961 to 1999. SETTING: University of California, San Francisco, Medical Center and affiliated hospitals. PATIENTS: We selected 107 patients with a history of radiation exposure who had undergone thyroid operations (81 total thyroidectomies) and 107 control patients who underwent comparable operations but had no history of radiation exposure. RESULTS: Among patients with a history of radiation exposure (mean age, 47.2 years), there was 1 recurrent nerve injury, 1 external nerve injury, 20 patients with transient hypocalcemia, and 1 patient with a hematoma. Among patients without a history of radiation exposure (mean age, 47.5 years), there were 2 recurrent nerve injuries, 18 patients with transient hypocalcemia, and 1 patient with a hematoma. All cases of hypocalcemia and recurrent nerve injury in both groups were transient. One patient had a permanent superior laryngeal nerve injury. In patients who underwent operations since January 1, 1990, duration of hospitalization was 1.2 days in patients with a history of radiation exposure (65 patients) and 1.1 days in patients without (101 patients). CONCLUSIONS: Our data document that the risk of transient and permanent complications after total thyroidectomy is similar in patients with and without a history of radiation exposure. The relatively low long-term complication rate supports prophylactic total thyroidectomy for patients with thyroid nodules and a history of radiation exposure.

Female↗
PubMed2004

Predictors of airway complications after thyroidectomy for substernal goiter.

HYPOTHESIS: Airway complications after thyroidectomy for substernal goiter can be predicted by preoperative symptom profiles, radiologic findings, or other factors. DESIGN: Retrospective review. Settings A university tertiary care center and a veterans' hospital. PATIENTS: Sixty patients with substernal goiter who underwent thyroidectomy between 1993 and 2002. MAIN OUTCOME MEASURES: Symptoms, preoperative radiologic findings, extent of thyroid resection, tumor size, and postoperative complications. RESULTS: Dysphagia was the most common preoperative symptom (n = 26), followed by dyspnea (n = 21), orthopnea (n = 13), and hoarseness (n = 6); 18 patients (30%) had superior vena caval obstruction. Thirteen patients (22%) were asymptomatic. Preoperative imaging identified tracheal deviation or compression in 45 patients (75%). Substernal goiter was resected via a cervical approach in 59 patients (98%). Of 47 patients with preoperative symptoms, 41 (87%) reported improvement postoperatively. Seven patients (12%) had postoperative airway complications: 1 developed a neck hematoma requiring reoperation, and 6 could not be immediately extubated; all 6 were successfully extubated after 1 to 10 days. Patients with airway complications were older (mean +/- SEM, 70.3 +/- 3.6 years vs 61.5 +/- 2.2 years), had larger goiters (mean +/- SEM, 210.7 +/- 37.0 g vs 112.2 +/- 7.7 g), and were more likely to have tracheal compression on preoperative imaging than those who did not have complications (P<.05). CONCLUSIONS: Most patients with substernal goiters underwent thyroid resection via a cervical approach with an improvement in symptoms. The few patients who developed postoperative airway complications were older, had larger goiters, and were more likely to have tracheal compression on preoperative imaging than those without airway complications.

Age Factors↗
PubMed2004

Tertiary hyperparathyroidism: histologic patterns of disease and results of parathyroidectomy.

HYPOTHESIS: Patients with tertiary hyperparathyroidism (THPT) commonly have parathyroid hyperplasia and should have a bilateral neck exploration with subtotal or total parathyroidectomy with autotransplantation to obtain long-term cure. DESIGN: A retrospective cohort study. SETTING: Tertiary referral medical center. PATIENTS: Thirty-four consecutive patients (21 women and 13 men; mean age, 48 years) who underwent neck exploration for THPT. MAIN OUTCOME MEASURES: Sites and histologic pattern of parathyroid disease, and postoperative normalization of serum calcium and parathyroid hormone levels. RESULTS: Twenty-seven patients underwent initial bilateral neck exploration and 7 patients underwent repeat neck exploration for persistent or recurrent THPT. The mean serum total calcium level was 11.2 mg/dL (2.8 mmol/L) (range, 10.3-13.5 mg/dL [2.6-3.4 mmol/L]) and the mean intact parathyroid hormone level was 355 ng/L (range, 95-1236 ng/L). The THPT was due to 4-gland hyperplasia in 33 patients and a single adenoma in only 1 patient. The parathyroid glands were in the normal position in 23 patients and in ectopic locations in 11 patients (8 intrathymic, 1 carotid sheath, 1 tracheoesophageal groove, and 1 intramuscular). Preoperative localizing studies did not identify ectopic or supernumerary glands in any of the patients (ultrasonography, 14 patients; technetium Tc 99m sestamibi, 15; and magnetic resonance imaging, 7). Persistent (n = 5) and recurrent (n = 2) THPT was more common in patients who had an initial 1- or 2-gland excision instead of subtotal or total parathyroidectomy with autotransplantation (P<.001). Four patients had transient hypocalcemia (<8.0 mg/dL [<2.0 mmol/L]), and no other permanent complications or deaths occurred. Biochemical cure was achieved in 94% of patients with a mean follow-up of 4.8 years. CONCLUSIONS: Tertiary hyperparathyroidism is usually due to multiple hyperplastic parathyroid glands, and patients who have initial limited parathyroidectomy have a higher risk of persistent or recurrent THPT.

Adolescent↗
PubMed2004

Reasons for conversion from laparoscopic to open or hand-assisted adrenalectomy: review of 261 laparoscopic adrenalectomies from 1993 to 2003.

Over the past decade, laparoscopic adrenalectomy has become the operation of choice for resecting adrenal tumors. However, few reported data exist regarding the reasons for conversion from laparoscopic to open or hand-assisted adrenalectomy. We retrospectively reviewed the records of 261 consecutive laparoscopic adrenalectomies performed by one surgeon between 1993 and 2003. Laparoscopic adrenalectomy could not be completed in 8 of the 261 patients (3%); four of the operations were converted to hand-assisted laparoscopic adrenalectomy and four to open adrenalectomy. The reasons for the conversion were as follows: In three patients the tumor was too adherent to surrounding structures to be resected laparoscopically; in three patients the tumor was found to have malignant features during laparoscopy, and the operation was converted to achieve proper resection margins; in two patients the tumors were too large (15 and 16 cm, respectively) to be safely removed laparoscopically. The eight resected tumors included three pheochromocytomas, one myelolipoma, one angiomyolipoma, one solitary fibrous tumor, one liposarcoma, and one metastatic hepatocellular carcinoma. There were no cases in which conversion was required emergently for bleeding or other intraoperative catastrophes. All eight of the tumors removed were at least 5 cm in size (range 5-16 cm). The mean length of hospitalization was 4.4 days (range 3-8 days).

Adrenal Gland Neoplasms↗
PubMed2004

Spatial ability, experience, and skill in laparoscopic surgery.

BACKGROUND: Previous research showing correlations between spatial ability and surgical skills has used participants in relatively early stages of training. Research in skill acquisition has shown that the role of cognitive abilities can diminish as skills become increasingly automatic. In this study, we explored the role of spatial ability in laparoscopic surgical skills in two groups, one experienced and the other relatively inexperienced. METHODS: Subjects were recruited from two videoscopic courses: an advanced course for experienced surgeons and a laparoscopic urological surgery course attended by participants with relatively little laparoscopic experience. Three measures were obtained: spatial abilities, videoscopic experience, and operative skills. RESULTS: A significant correlation (r = 0.393) was found between spatial ability and skills in the lower experience group but not among the experienced surgeons (r = 0.020). CONCLUSIONS: The results are consistent with the prediction that the importance of spatial ability in performance of laparoscopic skills should diminish with experience.

Clinical Competence↗
PubMed2004

Clinical manifestation of aldosteronoma.

Formerly, fewer than 1% of patients with hypertension were believed to have primary hyperaldosteronism; however, recent studies have suggested a higher prevalence, in 5% to 10% of patients with hypertension. Hypokalemia is not necessary for the diagnosis and is probably a sign of more advanced disease. The best diagnostic test is the plasma aldosterone concentration to plasma renin activity (PAC/PRA) ratio. Excess aldosterone level has a deleterious effect on the cardiovascular system. Aldosteronomas should be differentiated from idiopathic hyperaldosteronism (IHA),because they are curable by laparoscopic adrenalectomy.

Adenoma↗
PubMed2004

Should pheochromocytoma size influence surgical approach? A comparison of 90 malignant and 60 benign pheochromocytomas.

BACKGROUND: Diagnostic tests cannot reliably distinguish malignant from benign pheochromocytomas. Laparoscopic adrenalectomy for pheochromocytomas >6 cm is controversial because of a perceived increased risk of malignancy that is based on anecdotal reports and small series. The aim of this study was to determine if pheochromocytoma size should affect the choice of surgical approach. METHODS: Malignant pheochromocytomas in the Surveillance Epidemiology and End Results (SEER) database (1988-2000) were compared to benign pheochromocytomas in our institutional database (1993-2003). The sensitivity, specificity and likelihood ratio for tumor size to predict malignancy were calculated for both groups. RESULTS: Ninety malignant and 60 benign pheochromocytomas were compared. Overall, malignant pheochromocytomas were larger than benign pheochromocytomas (7.6 +/- 4.2 cm vs 5.3 +/- 2.3 cm). However, tumor size was not significantly different between malignant pheochromocytomas without local invasion or metastases and benign pheochromocytomas (6.1 +/- 3.1 cm vs 5.3 +/- 2.3 cm). In pheochromocytomas with local disease only, maximum likelihood ratio to predict malignancy was at a tumor size of greater than 8 cm (2.84). CONCLUSIONS: Although risk of malignancy increases with size for all pheochromocytomas, size does not reliably predict malignancy in pheochromocytomas with local disease only. Regardless of tumor size, laparoscopic adrenalectomy for pheochromocytoma should be converted to open adrenalectomy for difficult dissection, invasion, adhesions, or surgeon inexperience.

Adolescent↗