The Self-Locating Peritoneal Catheter: Fifteen Years of Experience

Magnetic resonance imaging in patients with self-locating peritoneal catheters: Is it safe?

The fact that self-locating catheters have a piece of metal at the tip leads to doubt and uncertainty around performing magnetic resonance imaging (MRI) in patients with this type of catheter. We simulated a peritoneum with a weighted catheter to ascertain how the catheter behaved during MRI scans in 1.5 T and 3 T machines. We also reviewed cases in which MRI had been performed in patients with this type of catheter. In the simulation, the tip of the self-locating peritoneal catheter caused a magnetic susceptibility artefact that made it difficult to see nearby areas, but it proved to be a safe device for MRI. 14 MRI scans were performed in patients with self-locating catheters, none in the abdominal area. There were no complications in the patients or the technique after performing MRI.

Magnetic resonance imaging in patients with self-locating peritoneal catheters: Is it safe?

The fact that self-locating catheters have a piece of metal at the tip leads to doubt and uncertainty around performing magnetic resonance imaging (MRI) in patients with this type of catheter. We simulated a peritoneum with a weighted catheter to ascertain how the catheter behaved during MRI scans in 1.5T and 3T machines. We also reviewed cases in which MRI had been performed in patients with this type of catheter. In the simulation, the tip of the self-locating peritoneal catheter caused a magnetic susceptibility artefact that made it difficult to see nearby areas, but it proved to be a safe device for MRI. 14 MRI scans were performed in patients with self-locating catheters, none in the abdominal area. There were no complications in the patients or the technique after performing MRI.

Obstrucción mecánica de colon producida por un catéter autoposicionante de diálisis peritoneal

Introdución: El catéter peritoneal resulta imprescindible para la realización de la diálisis peritoneal. Se han desarrollado distintos modelos y en 1996 apareció el catéter Autoposicionante con la intención de disminuir las disfunciones por desplazamiento gracias al peso de tungsteno de su extremo. Esta complicación condiciona su funcionamiento y la viabilidad de la técnica. CASO CLÍNICO: Presentamos el caso de un varón al que se coloca catéter Swan Neck con funcionamiento inicial bueno, pero que en tres meses necesita dos maniobras alfa por migraciones y termina precisando recambio de catéter, colocándose en esta ocasión un catéter Autoposicionante. Ya durante el periodo de cicatrización presenta nuevo desplazamiento y una tercera maniobra alfa permite reiniciar la técnica. A los tres meses ingresa para estudios por clínica abdominal; en la radiografía de abdomen se observa dilatación de asas, el TAC urgente muestra dilatación de ciego y colon hasta el cruce con el catéter de diálisis peritoneal, llegándose al diagnóstico de obstrucción mecánica de colon por catéter de diálisis. Se realiza laparoscopia y se recoloca la punta en la pelvis. Tras la cirugía el paciente evoluciona favorablemente y a los tres meses recibe trasplante renal de cadáver. A pesar optar por el catéter autoposicionante debido a su menor tasa de desplazamientos, en el caso de nuestro paciente se repite el episodio y además se asocia a una complicación grave.

Prospective Randomized Study Comparing a Single-Cuff Self-Locating Catheter with a Single-Cuff Straight Tenckhoff Catheter in Peritoneal Dialysis

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OBJECTIVES

Peritoneal dialysis (PD) catheters are critical to the success of the technique. However, few studies provide evidence about which design helps to reduce complications. Self-locating catheters (SLCs) are used to avoid displacement of the catheter tip. The incidence of mechanical and infectious complications and catheter survival rate were assessed in Tenckhoff PD catheters. ♦

DESIGN

The prospective randomized study compared drainage problems in 40 incident PD patients using a single-cuff SLCs and 38 patients using a single-cuff, straight Tenckhoff catheter (TC). ♦

RESULTS

No significant differences were observed in the number of complications in the Pre period (from the insertion of the catheter to the start of the technique); however, the number of complications was lower in the SLC group during Post (p = 0.021) and Total period (p = 0.048). The number of problems related to catheter malfunction for each period: Pre, Post, and Total, was significantly lower with SLCs vs TCs (p = 0.018, p = 0.001 and p = 0.003, respectively). Problems were solved more easily with SLCs, using laxatives, with less need for fluoroscopic placement and no need for surgical replacement, as opposed to the TC group: Pre (not significant), Post (p = 0.007), and Total (p = 0.011).Median survival was 39.6 months (30.9 - 48.3) for SLCs and 30.1 months (22.6 - 37.5) for TCs, which is not a significant difference. However, SLCs have a higher malposition-free survival rate. Multivariate logistic regression models only included the variable "type of catheter" as a predictor of malfunction during the Pre period (odds ratio [OR] = 4.154). The Post period included the variables, "type of catheter" (OR = 7.701) and "age" (OR = 1.047), and the Total period only included the variable "type of catheter" (OR = 4.487), which indicates an increased probability of malfunction with the use of TCs vs SLCs. The variables (gender, previous intra-abdominal surgery, body mass index (BMI) and diabetes mellitus) did not add predictive value to the models (p > 0.05). ♦

CONCLUSION

The study confirms the hypothesis that TCs have more malfunctions and a lower malposition-free survival rate than SLCs, and TCs are considered as the highest risk factor for malfunction during all study periods.