Lewis V. Owens

Focal adhesion kinase as a marker of invasive potential in differentiated human thyroid cancer.

AbstractBackground: The FAK gene encodes a 125-kDa tyrosine kinase (p125FAK) involved in signal transduction pathways used in cell adhesion, motility, and anchorage-independent growth. Because thyroid carcinomas have a wide variability in their propensity for invasion and metastasis, we studied the expression of FAK in a variety of thyroid tissues. Methods: We synthesized a recombinant N-terminal fragment of the human FAK protein and developed a specific polyclonal antisera. Using Western blot analysis, we assessed the levels of p125FAK expression in 30 human thyroid tissue samples from 27 patients that included paired normal and malignant specimens. Levels of FAK protein in individual tumors were quantitated by densitometric scanning of the immunoblots, and the results were correlated with tumor histology and biologic behavior. Results: The levels of FAK expression were directly correlated with thyroid carcinomas demonstrating the most aggressive phenotypes. The highest levels of p125FAK were seen in follicular carcinomas and tumors associated with distant metastatic foci. In contrast, neoplastic thyroid tissues with limited invasive potential, such as papillary carcinomas, follicular adenomas, and other nonmalignant thyroid lesions, showed minimal p125FAK expression. Conclusions: Overexpression of FAK may be part of a mechanism for invasion and metastasis of thyroid cancer. Furthermore, the levels of p125FAK may serve as a marker of biologic behavior in this disease.

Extrathoracic reconstruction of arterial occlusive disease involving the supraaortic trunks

PURPOSE The purpose of this study was to review the various extrathoracic reconstruction options in patients with occlusive disease of the supraaortic trunks and to define the efficacy of these procedures in maintaining graft patency and relieving symptoms. METHODS Forty-four consecutive patients underwent 47 extrathoracic bypass procedures of the supraaortic trunks for correction of symptomatic subclavian (SCA), common carotid (CCA) or innominate (INA) artery occlusive disease between July 1975 and May 1994. SCA stenosis (n = 27) was associated with upper extremity claudication (55%), vertebrobasilar insufficiency (15%), or both (30%). CCA stenosis (n = 14) was accompanied by hemispheric symptoms in 86% and global ischemia in 14%, whereas INA stenosis (n = 3) was associated with transient ischemic attacks (67%) and right arm ischemia (33%). RESULTS SCA revascularization included carotid-subclavian or carotid-axillary bypass (n = 19), axilloaxillary bypass (n = 8), and subclavian-carotid transposition (n = 3). CCA reconstructions included subclavian-carotid (SC) bypass (n = 13) and carotid-carotid bypass (n = 1). INA procedures included three axilloaxillary bypasses. Six patients had an associated carotid endarterectomy, and three underwent concomitant vertebral artery transpositions. Intraluminal shunts were not routinely used. Vein was used as a conduit in five procedures, and a prosthetic graft (23 Dacron, 16 polytetrafluoroethlyene) was used in the remainder. The average postoperative intensive care unit and hospital and hospital stay were 1 and 5 days, respectively. Follow-up was available in 43 of 44 patients (mean = 26.2 months). The perioperative mortality rate was 2.2% (one axilloaxillary). There were five graft occlusions in procedures involving the axillary artery (3 of 11 axilloaxillary, 2 of 7 carotid-axillary) as compared with one of 29 thromboses when the operation was confined to the supraclavicular fossa (p < 0.05) Relief of symptoms was achieved in all patients with patent grafts. There were no perioperative strokes in the series. Other complications included one brachial plexus neuropraxia (axilloaxillary) and four patients with phrenic nerve neuropraxia. CONCLUSION Extrathoracic revascularization of the supraaortic trunks is well tolerated and durable when operations are confined to the supraclavicular fossa and do not involve the axillary artery.

Insulinoma: Pitfalls in preoperative localization

In patients with biochemical evidence of insulinoma, many techniques have been advocated as the procedures of choice for diagnostic localization without a clear-cut consensus as to their utility. Despite the small size of insulinomas, 90% are solitary and nearly 100% are intrapancreatic. A commonly held belief is that once the diagnosis of autonomous hyperinsulinism is confirmed, it is necessary to secure as much information as possible about the precise location prior to surgery. Although frequently used, preoperative localization studies are expensive, potentially morbid, and worse yet, may be misleading. We present a case study in which the preoperative studies falsely localized the insulinoma to the pancreatic head. Since the introduction of intraoperative ultrasound (IOUS), it is now unusual not to identify and excise the insulinoma in patients undergoing exploration for functioning beta-islet cell lesions. Our experience, along with support from the literature, led us to recommend a simplified localization approach, namely IOUS combined with surgical palpation.

Percutaneous balloon fenestration and endovascular stent placement for Type B acute aortic dissection with renal ischemia: A case report

This case illustrates the feasibility and effectiveness of percutaneous balloon fenestration and endovascular renal artery stenting for Type B acute aortic dissection with associated renal ischemia. Percutaneous balloon fenestration and endovascular stent placement should be considered as an alternative to traditional surgical approaches to restore blood flow to arteries compromised by acute aortic dissection.