[Endovascular treatment of pararenal aortic aneurysms]. / Il trattamento endovascolare degli aneurismi dell'aorta pararenale.

Endovascular procedures have emerged as an attractive alternative technique for the repair of abdominal aortic aneurysms with an increasing popularity and diffusion. Even if technology progresses are developing more and more efficient grafts and devices, at the moment the endovascular treatment is still not applicable to all patients. The most common reason for patient exclusion remains an unsuitable proximal implantation site. Endografts with suprarenal fixation were studied for solving the problem of the proximal neck but results seem to be not so encouraging. At the moment pararenal aortic aneurysms, involving ostia of renal or visceral arteries, are usually excluded from endovascular treatment. The solution could be a custom-made graft for each single patient, with fenestrations or branches for renal and visceral arteries. The first clinical use of a fenestrated graft was by Park in 1996 and some groups are now studying different kinds of grafts, both in experimental and clinical studies, which are opening attractive new possibilities. At present results are only preliminary but this would be the first step towards the potential substitution of the entire aorta through endovascular techniques.

A methodological strategy for PAH genotyping in populations with a marked molecular heterogeneity of hyperphenylalaninemia.

The elucidation of the molecular basis of hyperphenylalaninemia in various world populations (PKU Consortium Database: http://www.mcgill/ca/pahdb/) has revealed a remarkable molecular heterogeneity at the locus encoding for phenylalanine hydroxylase. As a consequence, genotyping of HPA patients has prompted the establishment of an impressive number of mutatIon detection protocols. In spite of the large variety of methods proposed so far, no comprehensive strategy has been yet developed for the detection of PAH gene mutations. Therefore, new approaches, combining the advantages of individual methods are required, especially in populations with a high number of PAH gene mutations. In this study, we propose the use of Reverse Dot Blot Analysis within a general mutation protocol to simplify the genotyping of hyperphenylalaninemics in the very heterogeneous population of Sicily (Italy).

[Transluminal treatment in aneurysm of the abdominal aorta. Role of diagnostic imaging]. / Trattamento transluminale degli aneurismi dell'aorta addominale. Ruolo della diagnostica per immagini.

PURPOSE: To emphasize the importance of diagnostic imaging: a) in the selection of patients to be treated with the transluminal approach b) during stent-graft positioning c) in the follow-up of treated patients. MATERIAL AND METHODS: From January 1997 to May 1998, twenty-five patients with abdominal aortic aneurysms (AAA) were treated with transfemoral stent-grafts (AneuRx Medtronic). All patients were submitted to a preoperative study including digital angiography (DSA) and Spiral CT. Intraoperatively they underwent DSA and intravascular ultrasound (IVUS). Follow-up was performed with Spiral CT. RESULTS: Twenty-four bifurcated and one straight device were inserted in twenty-five patients with AAA. In two cases it was impossible to position the endoprosthesis due to narrow or tortuous artery access. Following the intention to treat criteria, the technical success rate was 92.5%. All the stents were patent and no dislodgement was observed at follow-up. Partial thrombosis of the stent was observed in three patients. Owing to incomplete distal covering, early endoleak occurred in one patient with an aortoiliac aneurysm; the positioning of two cuffs allowed a successful outcome. CT examination performed 6 months after positioning revealed the presence of endoleaks in three patients, due to persistence of lumbar and inferior mesenteric artery patency. The AAA was no more appreciable in five of the ten patients submitted to CT follow-up one year after the procedure. In three of ten cases it was reduced in size and in two patients there was no change. DISCUSSION: Spiral CT plays a basic role in the selection of patients because it helps assess the length and diameter of the proximal neck, thus permitting to choose the device to be inserted. Preoperative DSA is mandatory in the evaluation of size and tortuosity of the iliac arteries. IVUS allows to monitor the site of delivery during the maneuver and to make the final measurements while DSA plays a role in checking the correct positioning of the device and excluding the presence of endoleaks at the end of the procedure. Late follow-up with Spiral CT aims at demonstrating possible malfunctioning of the endoprosthesis and confirms the definitive exclusion of AAA. CONCLUSIONS: Diagnostic imaging plays a basic role in the endovascular treatment of AAA, much more than that required for traditional surgical treatment. In particular, pretreatment planning is critical and requires sophisticated imaging including Spiral CT with 3D reconstruction and angiographic evaluation using catheters with calibrated markers.