Palmaz stent

Fig. 14.6a-c. Type III endoleak due to incomplete seal at the junction between components, a Angiogram from left groin demonstrates a type III endoleak (white arrow) and a lumbar artery (black arrow), b Palmaz stent placement inflated to 12 mm.c Control angiogram shows no more endoleak... 

Palmaz stents are now available in large sizes allowing placement in the venae cavae. They are balloon expandable, spontaneously radiopaque, but rigid (Elson et al. 1992 Dodds et al. 1994 Bartorelli et al. 1995 Kamalesh et al. 1994 Carlson et al. 1995). 

Antonucci F, Salomonowitz E, Stuckmann G et al. (1992) Hemodialysis related venous stenoses treatment with self-expanding endovascular prostheses. Eur J Radiol 14 195-200 Bartorelli AL, Fabbiocchi F, Montorsi P et al. (1995) Successful transcatheter management of Palmaz stent embolization after superior vena caval stenting. Cathet Cardiovasc Diagn 34 162-166... 

Because of its smaller opening diameter, Palmaz stents have been used mainly in children (Filler et al. 1998 Furman et al. 1999) and only occasionally in the adult bronchial tree. Slonim et al. (1998) reported on Palmaz stent insertion in bronchial stenosis of three patients with malignant, inoperable obstructions (Slonim et al. 1998). Two patients had respiratory distress and one atelectasis. Immediately after stent placement, all patients had improvement of the respiratory distress or the atelectasis. The follow-up period ranged from 0.5 to 9.2 months. 

A larger patient population was reported by Beer et al. (1999). A total of 27 Palmaz stents were placed in 21 patients with malignant obstructive tracheobronchial obstructions (trachea, n=2 left main stem bronchus, n=8 intermediate bronchus, n=7 right main stem bronchus, n=l lobar bronchi, n=4). Following stent insertion, six patients had no further respiratory distress, and the remaining 15 patients reported relief of dyspnea. In seven patients, postobstructive pneumonia was successfully treated by stent placement. Mean survival time was 12 months. Restenosis occurred in four patients and was treated with redilation in three, and laser ablation in one patient. 

The Palmaz stent as a balloon expandable stent has a specific complication profile. Once the stent is compressed due to extrinsic forces, e.g., an enlarging tumor mass, adjacent vascular structures, or a vigorous cough, it has no abihty to reexpand. Compression of a Palmaz stent has been noted in a patient with a thoracic aortic aneurysm (Slonim et al. 1998), in a patient after severe coughing (Hautmann and Huber 1996), and in two patients with external malignant tumors (Beer et al. 1999). 

Deformation and migration of Palmaz stents in three patients brought the suitability of the stent for use in the tracheobronchial system into question (Perini et al. 1999). The authors encountered stent collapse in three patients at 44 days, 78 days and 362 days after initial placement, respectively. Three stents also showed signs of complete or partial migration. The authors decided to no longer use this stent type in the tracheobronchial tree. 

Beer M, Wittenberg G, Sandstede J, Beissert M, Schmidt M, Ender J, Krahe T, Hahn D (1999) Treatment of inoperable tracheobronchial obstructive lesions with the Palmaz stent. Cardiovasc Intervent Radiol 22 109-113 Bjarnason H, Cahill B, Klow NE et al. (1999) Tracheobronchial... 

Perini S, Gordon RL, Golden JA, LaBerge JM, Wilson MW, Kerlan RK (1999) Deformation and migration of Palmaz stents after placement in the tracheobronchial tree. J Vase Intervent Radiol 10 209-215... 

Palmaz JC, Laborde JC, Rivera FJ, et al. Stenting of the iliac arteries with the Palmaz stent experience with a multicenter trial. Cardiovasc Intervent Radiol 1992 15 291-297. 

Bergeron P. Pinot JJ, Poyen V, et al. Long-term results with the Palmaz stent in the superficial femoral artery. J Endovasc Surg 1995 2 161-167. 

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