Hamming, J.F.

Aortic customize: An in vivo feasibility study of a percutaneous technique for the repair of aortic aneurysms using injectable elastomer (Article)

2010-07-01T00:00:00Z

Objective: This study aimed to test a percutaneous technique for aneurysm-sac filling by means of in situ polymerisation in an in vivo model. Design: Aortic Customize is a new endovascular treatment concept for aortic aneurysms: a non-cross-linked liquid elastomer is injected to fill the aneurysm sac around a ballooncatheter. With this method, a compliant elastomer mould with a patent lumen is created. Material: The formulation used in the experiments consisted of a two-component additioncure liquid-silicone formulation, based on vinyl-terminated polydimethylsiloxane (PDMS). Methods: The concept of aneurysm-sac filling was tested in vivo in porcine experiments (nZ3). Results: In vivo porcine experiments with the sac-filling application showed successful exclusion of the created aneurysms with patent lumens and absence of endoleaks. The aneurysms were excluded successfully in the in vivo model, injecting elastomer through a 7-French catheter, filling up the entire aneurysm sac. Conclusions: These in vivo experiments demonstrate that the principle of aneurysm-sac filling by means of in situ curing is feasible, excluding the aneurysm and creating a new lumen. Further long-term animal experiments must be done prior to consideration of clinical application.

Factors predicting Outcome of total thyroidectomy in young patients with Multiple endocrine neoplasia type 2: A nationwide long-term follow-up study (Article)

2010-04-01T00:00:00Z

Background Multiple endocrine neoplasia type 2 (MEN 2) is caused by a RET mutation in chromosome 10. All MEN 2 patients develop medullary thyroid carcinoma (MTC). The age-related risk of MTC is associated with the type of RET mutation. Our aim was to identify prognostic factors associated with recurrent MTC in MEN 2 patients. Methods In a nationwide case-control study, all patients who underwent total thyroidectomy in the Netherlands under the age of 20 years were classified into standard (1), high (2), or very high risk (3) for MTC based on RET-mutation type. Disease-free patients were compared with those with recurrent disease. Results A total of 93 patients were included in the study. Sixty-six percent had MTC on histology, the youngest being 1 year old. Codon 634 was most affected. Sixteen (18%) patients had persistent or recurrent disease, one of whom died. Significantly associated determinants of outcome in univariate analysis were higher age at surgery, no age-appropriate prophylactic surgery according to risk level, elevated preoperative calcitonin levels, affected codon, and the presence of lymph node metastases at surgery. On multivariate analysis only age of surgery was the single independent factor associated with persistent disease. Conclusions Prophylactic thyroidectomy beyond the recommended age is associated with persistent/recurrent disease. In addition, codon 634 mutation is associated with a high risk of recurrence requiring early surgery for all these patients.

Resection of carotid body tumors: Results of an evolving surgical technique (Article)

2008-05-01T00:00:00Z

OBJECTIVE: To evaluate a modified technique for carotid body tumor (CBT) resection. BACKGROUND: Resection of CBT can lead to substantial postoperative morbidity because of a rich vascularization and close connection to neurovascular structures. The impact of a modified surgical technique on postoperative outcome was evaluated and compared with a historical group and the literature. METHODS: Medical records of patients who underwent CBT surgery at Leiden University Medical Center between 1963 and 2005 were retrospectively reviewed. Before 1992, a standard approach was conducted. After 1992, most tumors were resected using an alternative technique, working in a craniocaudal fashion from skull base to carotid bifurcation. Data were reported as details of the pre, intra-, and postoperative periods. RESULTS: A total of 111 CBT resections (69 standard, 42 craniocaudal) were performed in 94 patients (44 male/50 female, mean age 41). The standard group consisted of 39 Shamblin I (56%), 22 II (32%), and 8 III (12%) tumors. The craniocaudally approached CBT included 12 Shamblin I (29%), 13 II (31%), and 17 III (40%) tumors. The mean blood loss was 901 mL (standard operations) versus 281 mL (craniocaudal approach, P < 0.0005). Persistent cranial nerve damage was encountered after 26 (23%) of 111 operations; 21 after the standard operations (30% within this group, including 3 preexistent nonresolved cranial nerve deficits); and 5 (12%, including 2 due to additional vagal body resections) after the craniocaudal operations (P = 0.025). CONCLUSIONS: The craniocaudal dissection technique of a CBT can be applied with little blood loss, thereby reducing the risk of postoperative morbidity.

Reduction of blood pressure, plasma cholesterol, and atherosclerosis by elevated endothelial nitric oxide. (Article)

2002-12-13T00:00:00Z

In the vascular system, nitric oxide is generated by endothelial NO synthase (eNOS). NO has pleiotropic effects, most of which are believed to be atheroprotective. Therefore, it has been argued that patients suffering from cardiovascular disease could benefit from an increase in eNOS activity. However, increased NO production can cause oxidative damage, cell toxicity, and apoptosis and hence could be atherogenic rather than beneficial. To study the in vivo effects of increased eNOS activity, we created transgenic mice overexpressing human eNOS. Aortic blood pressure was approximately 20 mm Hg lower in the transgenic mice compared with control mice because of lower systemic vascular resistance. The effects of eNOS overexpression on diet-induced atherosclerosis were studied in apolipoprotein E-deficient mice. Elevation of eNOS activity decreased blood pressure ( approximately 20 mm Hg) and plasma levels of cholesterol (approximately 17%), resulting in a reduction in atherosclerotic lesions by 40%. We conclude that an increase in eNOS activity is beneficial and provides protection against atherosclerosis.