Biomedical subjects

Cord Sturgeon

Publications and source records attributed to Cord Sturgeon.

17 recordsLinked to original sources

PubMed2006

What is the link between nonlocalizing sestamibi scans, multigland disease, and persistent hypercalcemia? A study of 401 consecutive patients undergoing parathyroidectomy.

BACKGROUND: We hypothesized that nonlocalizing sestamibi scans would correlate with multigland disease and persistent primary hyperparathyroidism. METHODS: We reviewed records for 401 consecutive patients who underwent parathyroidectomy from 1999 to 2004. Gender, age, preoperative imaging, surgical findings, gland weight and volume, and 6-month calcium levels (Ca) were examined. RESULTS: We identified 289 women and 112 men, 297 of whom had a preoperative sestamibi scan localized to a single gland (localized group; LG). Ninety-six percent of the LG were found to have single-gland disease, and 4% had multigland disease (MGD). In the nonlocalized group (NLG), 76% had single-gland disease and 24% MGD. Mean gland weight was greater in the LG than in the NLG (1128 mg vs 699 mg; P < .05). Mean gland volume was larger in the LG (1.34 cc vs 0.89 cc; P < .05). A localizing sestamibi scan had a positive predictive value (PPV) of 96% and a likelihood ratio of 2.29 for predicting "curative" intraoperative parathyroid hormone drop after removal of a single abnormal gland. Patients were stratified into normocalcemic (NCa) and hypercalcemic (HCa) groups based on 6-month postoperative serum calcium data (n = 328). HCa incidence at 6 months did not differ significantly between the LG (5%) and NLG (3%). A localizing scan had a PPV of 95% for normocalcemia at 6 months. A nonlocalizing scan had a PPV of 21% for HCa at 6 months. CONCLUSIONS: Nonlocalizing sestamibi scans were more common in primary hyperparathyroidism with MGD and were associated with smaller-volume abnormal glands found at operation. Preoperative sestamibi scan-results did not predict HCa at 6 months.

Adenoma↗

PubMed2006

Risk assessment in 457 adrenal cortical carcinomas: how much does tumor size predict the likelihood of malignancy?

BACKGROUND: Laparoscopic adrenalectomy for tumors > 6 cm is controversial because of the risk of malignancy, but data to support this position are mostly from small series. The recent NIH consensus conference did not make a definitive recommendation about management of 4- to 6-cm nonfunctioning incidentalomas. STUDY DESIGN: Adrenocortical carcinomas (ACC) recorded in the Surveillance, Epidemiology, and End Results (SEER) database (1988 to 2000) were compared with benign functional or nonfunctional adrenal cortical adenomas (excluding aldosteronomas) operated on at our institution between January 1, 1993, and July 1, 2003. Data were compared using t-tests, chi-square tests, likelihood ratios, and receiver operating characteristic (ROC) curves. RESULTS: We identified 457 patients with ACC and 47 patients with adrenal cortical adenomas; 376 and 44 neoplasms, respectively, had tumor size data available. Tumor size was larger in ACC (12.0 +/- 5.6 versus 4.2 +/- 1.9 cm, mean +/- SD, p < 0.05). For ACC presenting with local disease, the sensitivity, specificity, and likelihood ratios of tumor size to predict malignancy were 96%, 52%, and 2.0, respectively, for tumors > or = 4 cm; 90%, 80%, and 4.4 for tumors > or = 6 cm; 77%, 95%, and 16.9 for tumors > or = 8 cm; and 55%, 98%, and 24.4 for tumors > or = 10 cm. Assuming a pretest probability of malignancy of 5%, the likelihood ratios derived from this study yield a posttest probability of 10%, 19%, and 47% for cancer in adrenal cortical tumors > or = 4 cm, > or = 6 cm, and > or = 8 cm, respectively. CONCLUSIONS: These data suggest that size is useful for predicting malignancy, and that at a size threshold of > or = 4 cm, the likelihood of malignancy doubles (to 10%) and it is more than ninefold higher for tumors > or = 8 cm (47%).

Adolescent↗

PubMed2006

Minimally invasive video-assisted thyroidectomy for follicular neoplasm: is there an advantage over conventional thyroidectomy?

BACKGROUND: Minimally invasive video-assisted thyroidectomy (MIVAT) is safe and effective for selected patients, but its advantages are not clearly defined. Results of MIVAT for follicular neoplasms at a single institution were retrospectively evaluated to define its advantages or disadvantages. METHODS: Between October 2002 and May 2004, 22 patients underwent MIVAT. Twenty-six patients who underwent conventional thyroidectomy during the same time period served as matched controls. Operative times, pathologic findings, complications, analgesic requirements, and incision lengths were retrospectively evaluated. RESULTS: Four MIVAT and three conventional surgery patients underwent total thyroidectomy. Eighteen MIVAT and 23 conventional patients underwent hemithyroidectomy. The operative time (mean +/- SEM) for hemithyroidectomy was 102 +/- 4 minutes for MIVAT and 86 +/- 3 minutes for conventional surgery (P < .05). In subgroup analysis that excluded patients with thyroiditis, operative times were not significantly different: MIVAT, 99 +/- 4 minutes; conventional, 88 +/- 4 minutes. The mean incision length was 2.3 +/- .5 cm in the MIVAT group. Conventional thyroidectomy was performed through a 4- to 5-cm incision. The average amount of narcotic used was not significantly different (intravenous, 9.9 +/- 3.1 mg [MIVAT] vs. 12.4 +/- 3.8 mg; oral, 10.3 +/- 4.2 mg [MIVAT] vs. 3.5 +/- 2.0 mg). The conventional group received more cyclooxygenase 2 inhibitor (527 +/- 9 mg vs. 187 +/- 84 mg; P < .05). One patient in each group experienced transient hoarseness. There were no cases of permanent hypoparathyroidism or recurrent laryngeal nerve injury in either group. CONCLUSIONS: MIVAT is as safe and effective as conventional thyroidectomy and is associated with similar narcotic analgesic requirements, but it can be performed through smaller incisions. Operative times were significantly longer for MIVAT, but when patients with thyroiditis were excluded, operative times were not significantly different.

Adenocarcinoma, Follicular↗

PubMed2006

Which intraoperative parathyroid hormone assay criterion best predicts operative success? A study of 352 consecutive patients.

HYPOTHESIS: The 6 published criteria for predicting curative parathyroid resection by means of intraoperative parathyroid hormone (IOPTH) assay are not equivalent. DESIGN: Retrospective review of 352 patients undergoing parathyroidectomy for primary hyperparathyroidism from January 1, 1999, to December 31, 2004. We evaluated 6-month postoperative IOPTH values and serum calcium levels. SETTING: Tertiary referral center. MAIN OUTCOME MEASURES: The IOPTH values at baseline (preincision and preexcision) and at 5 and 10 minutes after parathyroidectomy were reviewed according to the Miami criterion (>50% drop from highest baseline IOPTH level at 10 minutes after excision), criterion 1 (>50% drop from preincision IOPTH level at 10 minutes), criterion 2 (>50% drop from highest baseline IOPTH level at 10 minutes and final IOPTH level within the reference range), criterion 3 (>50% drop from highest baseline IOPTH level at 10 minutes and final IOPTH level less than the preincision value), criterion 4 (>50% drop from highest baseline IOPTH level at 5 minutes), and criterion 5 (>50% drop from preexcision IOPTH level at 10 minutes). RESULTS: Criterion 2 had sensitivity of 88%, specificity of 22%, positive predictive value of 97%, and negative predictive value of 6%. Criterion 2 had good agreement with criteria 1 and 3. Of patients whose IOPTH level drop satisfied criterion 2 but not criterion 1, 14% had postoperative hypercalcemia at 6 months. When criterion 2 was not satisfied but criteria 1, 3, 4, and 5 and the Miami criterion were, failure rates were 0%, 4%, 7%, 6%, and 9%, respectively. CONCLUSIONS: Satisfying criterion 2 had a high operative success but resulted in additional unnecessary surgical exploration. Criterion 1 was better at predicting postoperative normocalcemia than criterion 2.

Biomarkers↗

PubMed2006

Does familial non-medullary thyroid cancer adversely affect survival?

BACKGROUND: Familial non-medullary thyroid cancer (FNMTC) is associated with a higher rate of multifocality and a higher recurrence rate than sporadic thyroid cancer. However, the effect of FNMTC on life expectancy is unknown. MATERIAL AND METHODS: Using data from our FNMTC database, we calculated life expectancy and survival rates after diagnosis of FNMTC and compared the results with the rates for unaffected family members and for the standard US population. Overall life expectancy and survival rates were calculated using the Kaplan-Meier method. We compared patients from families with 2 affected members with patients from families with > or = 3 affected members. We also compared patients diagnosed in a known familial setting (index cases and subsequent cases) with patients diagnosed before the familial setting was recognized. RESULTS: There were 139 affected patients with 757 unaffected family members. The mean age at diagnosis was 40.8 +/- 13.9 years and the mean follow-up time was 9.4 +/- 11.7 years. Ten patients died of thyroid cancer during follow-up. The life expectancy of patients with FNMTC was similar to that of their unaffected family members. Survival was significantly shorter for patients with 3 or more affected family members, for patients diagnosed before the familial setting was recognized, and for patients with anaplastic cancer. CONCLUSIONS: Our results suggest that FNMTC may be more aggressive than sporadic thyroid cancer, particularly in families with 3 or more affected members. However, when recognized and treated appropriately, it does not significantly shorten the overall life expectancy of the affected patients.

Adenocarcinoma, Follicular↗

PubMed2006

Identification and treatment of aggressive thyroid cancers. Part 1: subtypes.

Most thyroid cancers are slow-growing, easily treatable tumors with an excellent prognosis after surgical resection and targeted medical therapy. Unfortunately, 10% to 15% of thyroid cancers exhibit aggressive behavior and do not follow an indolent course. Approximately one-third of patients with differentiated thyroid cancers will have tumor recurrences. Distant metastases are present in about 20% of patients with recurrent cancer. Approximately half of patients with distant metastases die within 5 years. The loss of the ability to concentrate radioiodine and produce thyroglobulin is a sign of dedifferentiation, which occurs in about 30% of patients with persistent or recurrent thyroid cancer. Dedifferentiation is associated with poorer responses to conventional therapy and difficulty monitoring tumor burden. Clinicians must identify tumors with more aggressive biology and treat them accordingly with more aggressive regimens. Part 1 of this two-part article describes in detail the distinct types of thyroid cancer, as well as risk factors, outcomes, and prognostic factors, with a focus on thyroid cancers of follicular cell origin. Part 2, which will appear in next month's issue, covers risk assessment and staging, findings that suggest the presence of aggressive tumors, recurrent/metastatic disease, and the value of treatment with chemotherapy and external-beam radiotherapy. Experimental treatments utilizing molecular targets, redifferentiation agents, and gene therapy are covered briefly as well.

Antineoplastic Agents↗

PubMed2006

Identification and treatment of aggressive thyroid cancers. Part 2: risk assessment and treatment.

Most thyroid cancers are slow-growing, easily treatable tumors with an excellent prognosis after surgical resection and targeted medical therapy. Unfortunately, 10% to 15% of thyroid cancers exhibit aggressive behavior and do not follow an indolent course. Approximately one-third of patients with differentiated thyroid cancers will have tumor recurrences. Distant metastases are present in about 20% of patients with recurrent cancer. Approximately half of patients with distant metastases die within 5 years. The loss of the ability to concentrate radio-iodine and produce thyroglobulin is a sign of dedifferentiation, which occurs in about 30% of patients with persistent or recurrent thyroid cancer. Dedifferentiation is associated with poorer responses to conventional therapy and difficulty monitoring tumor burden. Clinicians must identify tumors with more aggressive biology and treat them accordingly with more aggressive regimens. Part 1 of this two-part article, which appeared in March, described in detail the distinct types of thyroid cancer, as well as risk factors, outcomes, treatment, and prognostic factors, with a focus on thyroid cancers of follicular cell origin. Part 2 covers risk assessment and staging, findings that suggest the presence of aggressive tumors, recurrent/metastatic disease, and treatment with chemotherapy and external-beam radiotherapy. Experimental treatments utilizing molecular targets, redifferentiation agents, and gene therapy are covered briefly as well.

Antibodies, Monoclonal↗

PubMed2005

The missing thyroid.

BACKGROUND: Several patients have been referred to our practice after having undergone attempted thyroidectomy, during which the thyroid gland was not found. These patients were reviewed to identify factors associated with failure to identify or adequately resect the thyroid. STUDY DESIGN: Patients referred for a "missed thyroid" between October 1, 1990 and December 31, 2002, were reviewed retrospectively. Seven patients who underwent neck exploration for thyroid cancer (n=6) or Graves' disease (n=1) were identified. Surgical indications, history of neck operations, means of recognizing the complication, incision location, and intraoperative and pathologic findings were analyzed. RESULTS: The thyroid was missed on initial exploration in four patients and in the second or third operation in three patients. In three patients, the surgeon misidentified the thymus (two patients) or nodal tissue (one patient) as the thyroid gland. In one patient, the thyroid could not be identified. In one patient, the thyroid was deemed unresectable because of scar tissue. In two patients, an inadequate "near-total" thyroidectomy was performed. In five patients with long necks, the neck incision was too far below the cricoid cartilage. CONCLUSIONS: Failure to identify the thyroid gland at the normal anatomic position was associated with low cervical incisions and a history of earlier neck operations. These findings emphasize the need for improved understanding of thyroid anatomy, embryology, localization procedures, and surgical technique.

Female↗

PubMed2005

From incidentaloma to adrenocortical carcinoma: the surgical management of adrenal tumors.

In this article we review the management of benign and malignant adrenal tumors, with an emphasis on oncologic concerns. Concise, logical guidelines for the diagnosis and operative treatment of incidentalomas, aldosteronomas, adrenal Cushing syndrome, virilizing and feminizing adrenal tumors, isolated adrenal metastases, and adrenocortical carcinoma are provided. We also discuss the choice of optimal surgical approach for performing adrenalectomy (laparoscopic, open, hand-assist).

Adrenal Cortex Neoplasms↗

PubMed2005

Familial nonmedullary thyroid cancer.

Familial nonmedullary thyroid cancer (FNMTC) is a syndrome of familial clustering of thyroid cancers of follicular cell origin. It is characterized by multifocality, early onset, more recurrences, and a higher degree of aggressiveness than nonfamilial thyroid cancers of follicular cell origin. An autosomal dominant inheritance pattern with reduced penetrance appears likely in most pedigrees. Although several candidate genes responsible for isolated clinical variants of FNMTC have been identified in single families, the gene(s) responsible for the vast majority of FNMTC cases has yet to be identified. Members of FNMTC cohorts should be followed longitudinally with physical examination and ultrasonography, and aggressively treated when cancer is diagnosed. When cancer is diagnosed, total thyroidectomy should be performed, and most patients should have a prophylactic central neck dissection and a therapeutic lateral functional neck dissection, postoperative radioiodine ablation and thyroid-stimulating hormone (TSH) suppressive therapy. Close follow-up with stimulated thyroglobulin levels, neck ultrasounds, and radioiodine scans are also central to the management strategy.

Humans↗

PubMed2004

Persistent and recurrent hyperparathyroidism.

More than 95% of patients with primary hyperparathyroidism (HPT) will be cured at initial operation by an experienced surgeon. Despite this success rate, persistent and recurrent HPT remain challenging clinical entities. The most cost effective and safest treatment for persistent and recurrent HPT is avoidance by successful first operation. The contributors to treatment failure can be categorized into factors related to the initial surgical procedure, anatomic variability, and the biology of disease. An understanding of the factors that commonly contribute to treatment failure can help prevent persistent and recurrent disease and plays an integral role in planning subsequent surgical approaches. Once a biochemical diagnosis of persistent or recurrent HPT is confirmed, a thorough evaluation of previous operative, pathology, and radiology reports is essential. Localization procedures supplement this information and help direct the reoperative approach. When complementary noninvasive studies, such as ultrasound, sestamibi, and magnetic resonance imaging are negative, equivocal, or discordant, invasive tests (eg, selective venous sampling for parathyroid hormone levels) are warranted. Intraoperative ultrasound and gamma-probe localization are of questionable value, but intraoperative parathyroid hormone assays help facilitate these challenging repeat dissections. Repeat parathyroid exploration is associated with more complications and fewer cures compared to the initial explorations and should only be undertaken by an experienced surgeon in a center that can provide expert preoperative localization, adjunctive intraoperative tools, and cryopreservation of parathyroid tissue when necessary. Although controversy exists regarding indications for reoperative treatment for persistent or recurrent HPT, parathyroidectomy remains the only curative treatment option. Surgery should be considered first-line treatment in most circumstances.

Diet↗

PubMed2004

Laparoscopic adrenalectomy for malignancy.

Laparoscopic adrenalectomy for primary malignancies and tumors metastatic to the adrenal is controversial. Most studies demonstrate that results of laparoscopic adrenalectomy for malignant lesions are similar to those of open adrenalectomy, without its morbidity. The results of laparoscopic adrenalectomy for tumor metastases suggest that it may benefit patients who have a metachronous metastasis from any of a variety of primary tumors. Selective laparoscopic adrenalectomy for potentially malignant tumors requires seeking signs of local invasion, lymphadenopathy, or distant metastasis; there are no other reliable preoperative criteria of malignancy. Diagnostic laparoscopy may be useful, and in some cases, may establish a diagnosis. Laparoscopic adrenalectomy should be cautiously performed, with the goals of achieving complete tumor resection without disruption of the adrenal capsule.

Adrenal Gland Neoplasms↗

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↗

PubMed2004

Laparoscopic surgery for melanoma metastases to the adrenal gland.

The probability of developing cutaneous melanoma is now predicted to be one in 55 for males and one in 88 for females. Although melanoma is relatively uncommon compared with other malignancies such as breast (one in seven) or prostate cancer (one in six), the incidence is growing at an alarming rate. The development of novel strategies for the management of advanced disease will become even more urgent and require continued and controlled investigations over the next 10 years. Surgery is effective for the palliation of isolated resectable metastases. However, most patients with Stage IV melanoma have widespread disease and are not cured by metastasectomy. For the few individuals with isolated adrenal metastases from melanoma, complete resection appears to confer a survival advantage. New data are emerging about the efficacy and outcome of laparoscopic adrenalectomy for malignant lesions. However, the natural history of laparoscopic surgery for these lesions is still unknown. The indications for and limitations of laparoscopic adrenalectomy for metastatic melanoma are discussed.

Adrenal Gland Neoplasms↗

PubMed2003

Early experience employing a linear hepatic parenchyma coagulation device.

BACKGROUND: In recent years, hepatic resection for primary and metastatic disease has been facilitated by improved anesthetic and surgical techniques, as well as by the application of new technologies. Historically, the major complications associated with hepatic resection have been postoperative bleeding, bile leak, and liver failure. Resection techniques and devices that minimize hemorrhage and bile leak, and enable the preservation of functional hepatic parenchyma, have been useful in the surgical management of liver tumors. METHODS: Herein, the use of a radiofrequency powered device for the pretransection coagulation of hepatic tissue that simultaneously seals blood vessels and bile ducts 3 mm in diameter or smaller is described. RESULTS: Early results from our single-center experience with the use of this linear radiofrequency device are reported. Seven patients underwent liver resection for either hepatocellular carcinoma or colorectal cancer metastases. There were no postoperative bile leaks, hemorrhage, or hepatic insufficiency. No transfusions were required, and the mean estimated blood loss for the parenchymal transection phase was less than 165 cc. CONCLUSIONS: The linear radiofrequency device is expedient for the pretransection coagulation of hepatic tissue and, thus, facilitates liver resection.

Aged↗

PubMed2003

Gastrointestinal stromal tumors: a spectrum of disease.

The majority of gastrointestinal stromal tumors (GIST) express c-kit, a growth factor receptor with tyrosine kinase activity. Mutations in the c-kit proto-oncogene may lead to constitutive ligand-independent activation of c-kit and subsequent neoplastic transformation. Selective tyrosine kinase inhibitors target this property of GIST and have become the standard chemotherapy for metastatic or unresectable tumors. The mainstay of treatment, however, continues to be complete surgical resection. Tyrosine kinase inhibitors may prove expedient for adjuvant therapy, and are currently the focus of clinical trials conducted by the ACOSOG, RTOG, and ACRIN. It is important to distinguish GISTs from other mesenchymal tumors of the GI tract because of differences in natural history, as well as the efficacy of treatments targeting the GIST tyrosine kinase.

Aged↗

PubMed2002

Mesenchymal stem cells suppress lymphocyte proliferation in vitro and prolong skin graft survival in vivo.

OBJECTIVE: Mesenchymal stem cells (MSCs), multipotential cells that reside within the bone marrow, can be induced to differentiate into various components of the marrow microenvironment, such as bone, adipose, and stromal tissues. The bone marrow microenvironment is vital to the development, differentiation, and regulation of the lymphohematopoietic system. We hypothesized that the activities of MSCs in the bone marrow microenvironment might also include immunomodulatory effects on lymphocytes. METHODS: Baboon MSCs were tested in vitro for their ability to elicit a proliferative response from allogeneic lymphocytes, to inhibit an ongoing allogeneic response, and to inhibit a proliferative response to potent T-cell mitogens. In vivo effects were tested by intravenous administration of donor MSCs to MHC-mismatched recipient baboons prior to placement of autologous, donor, and third-party skin grafts. RESULTS: MSCs failed to elicit a proliferative response from allogeneic lymphocytes. MSCs added into a mixed lymphocyte reaction, either on day 0 or on day 3, or to mitogen-stimulated lymphocytes, led to a greater than 50% reduction in proliferative activity. This effect could be maximized by escalating the dose of MSCs and could be reduced with the addition of exogenous IL-2. In vivo administration of MSCs led to prolonged skin graft survival when compared to control animals: 11.3 +/- 0.3 vs 7 +/- 0. CONCLUSIONS: Baboon MSCs have been observed to alter lymphocyte reactivity to allogeneic target cells and tissues. These immunoregulatory features may prove useful in future applications of tissue regeneration and stem cell engineering.

Animals↗