Micronester—A New Pushable Fibered Microcoil for Embolotherapy

Prognostic factors in endovascular treated pelvic haemorrhage after blunt trauma

Background

Angioembolization is the method of choice for treating haemorrhage after blunt pelvic trauma. The aim of this study was to determine technical factors related to endovascular procedures which might be related to patient outcome.

Methods

This retrospective study included 112 consecutive patients (40 women and 72 men; mean age 57.2 ± 20.0).

Results

There were age peaks at 43 and at 77 years. Patients over 65 years had mainly “low-energy” trauma; younger patients were more likely to have polytraumas. Younger patients were more severely injured and had more surgical interventions, larger haematoma volumes, lower Hb levels and required more transfusions than older patients. Women were older than men, had fewer surgeries and waited longer for an angiography (p < 0.05 each). Logistic regression analyses identified the injury severity score (ISS) as relevant for survival before age, haematoma volume and Hb. Propensity score analyses showed that in addition to the need for transfusions, haemoglobin, and haematoma volume, the length of the coils and the number of microcoils used were relevant (p < 0.05 each). The location of haemorrhage in peripheral parietal arteries (superior and inferior gluteal artery) was an influencing factor for re-angiographies, which were associated with considerably longer hospital stays of more than 40 days. Fewer particles had generally been used in these patients.

Conclusions

The use of too few coils and not using microparticles in angioembolization for pelvic haemorrhage are major influencing factors for the mortality or re-angiography rate. Special attention should be given to thorough peripheral embolization with microcoils, in particular for haemorrhage from the parietal branches of the internal iliac artery.

MicroNester coils as an adjunct to endovascular embolization

OBJECTIVES/BACKGROUND

In June 2003, detachable balloons were removed from the US market and were supplanted with coil embolization for parent artery sacrifice in difficult or nonsurgical aneurysms and other vascular pathologies. The current series examines the use of MicroNester pushable coils (Cook Medical, Bloomington, IN) as a low-cost and effective adjunct to detachable coils in the treatment of selected neurovascular pathologies.

METHODS

A retrospective analysis of all patients undergoing neurointerventional procedures from November 2003 through May 2008 was performed to identify patients in whom MicroNester coils were used as part of treatment. Analysis of coil type and number as well as pathology was performed.

RESULTS

MicroNesters were used in 26 cases, of which 21 were for arterial sacrifice--19 for the internal carotid artery and 2 for the vertebral artery. Fourteen were performed for intracranial aneurysms, 3 for pseudoaneurysms, 2 for carotid cavernous fistulae, 1 for a carotid blowout, and 1 for an arteriovenous malformation. Five additional procedures were transvenous, for treatment of dural arterial venous fistulae. The mean number of coils for artery sacrifice was 13, with an average of 10 MicroNesters. For transvenous embolizations, the means were 30 and 6, respectively.

CONCLUSION

MicroNesters are not the coil of choice for most neurointerventional procedures because they are not retrievable. However, when parent artery sacrifice or transvenous occlusion of dural arteriovenous fistulas is the goal, MicroNesters are a relatively inexpensive and equally effective alternative to more expensive, detachable coils and can reduce the procedural costs by $3600 to $6000 for the current series.

MicroNester coil for neurointervention

A MicroNester coil (MNC) was developed from the Nester coil with a 0.018-in microcatheter. The most specific feature of the MNC is the extended length of 14 cm. Neurointervention involving the MNC was undertaken in 11 patients. Intervention procedures were transvenous embolization for a dural arteriovenous fistula in 4 patients, transarterial embolization for a dural arteriovenous fistula in 2, parent artery occlusion for a cerebral aneurysm in 4, and stent-assisted embolization for a carotid artery dissection in 1. A push technique through microcatheter was used to deploy the MNCs. The MNCs were successfully placed into the venous sinus lesion, feeding artery, parent artery of the aneurysm, and the pseudoaneurysm. There were no major technical complications resulting in morbidity. The postoperative course was uneventful except in 2 cases in which the occluded vessel recanalized. Use of MNCs was safe and feasible for embolization of cerebrovascular lesions. Fewer coils are required in embolization when using MNCs.

Use of N-butyl cyanoacrylate in implantation of a port-catheter system for hepatic arterial infusion chemotherapy with the fixed-catheter-tip method: is it necessary?

OBJECTIVE

The purpose of our study was to evaluate the usefulness of N-butyl cyanoacrylate (NBCA) in addition to microcoils in the percutaneous implantation of a port-catheter system for repeated hepatic arterial infusion chemotherapy with the fixed-catheter-tip method.

MATERIALS AND METHODS

We retrospectively studied 166 consecutive patients with unresectable advanced liver cancer for whom a port-catheter system was percutaneously implanted with its tip fixed at the gastroduodenal artery with microcoils. In 107 patients, NBCA was also used for catheter tip fixation. We compared this group with a control cohort of 59 patients who did not receive NBCA. Outcomes, including rate of success in implantation, details of embolic agents for fixation, and occurrence of complications related to catheter placement that would prohibit continuation of chemotherapy if not corrected, were compared.

RESULTS

In all, port-catheter placement was successful. However, 38 complications occurred in 32 patients. Catheter dislocation occurred in nine. Hepatic artery obstruction or severe stenosis was seen in 10. Recanalization of a once-embolized gastroduodenal artery was found in two patients. The rate of dislocation did not differ significantly between patients in whom NBCA was and those in whom it was not used. However, hepatic artery obstruction appeared at a significantly higher rate, and recanalization of a gastroduodenal artery at a significantly lower rate, in patients in whom the catheter tip was fixed with NBCA.

CONCLUSION

The use of NBCA correlated with a higher rate of hepatic artery obstruction. The use of NBCA should not always be required in port-catheter implantation with the fixed-catheter-tip method.

Value of Micronester coils in port-catheter implantation for continuous hepatic arterial infusion chemotherapy with fixed catheter tip method

To retrospectively evaluate the use of Micronester coils in port-catheter implantation with the fixed catheter tip method in comparison with other previously used coils. The cohort of this study was 143 consecutive patients with unresectable advanced liver cancer for whom a port-catheter system was percutaneously implanted. In the most recent 32 patients, Micronester coils were used for catheter tip fixation. Details of embolic agents for fixation, persistent blood flow beyond the distal end of the indwelling catheter, and complications were compared between cases without and with Micronester coils. In all, percutaneous port-catheter placement was successful. Mean number of coils used for fixation was 4.2 without Micronester coils vs. 2.5 with Micronester coils. N-butyl cyanoacrylate (NBCA)-Lipiodol was additionally used for catheter tip fixation in 85.6% of 111 procedures without Micronester coils and in 50% of 32 using Micronester coils. The gastroduodenal artery beyond the distal end was not detected at the final examination after any procedure. Catheter dislocation occurred in five and hepatic arterial obstruction or severe stenosis in eight. The number of coils used and necessity of NBCA-Lipiodol could be decreased with usage of Micronester coils without decreasing fixation ability compared to other coils.

New embolization microcoil consisting of firm and flexible segments: preliminary clinical experience

PURPOSE

To describe the preliminary clinical experience with a new embolization microcoil.

METHODS

The microcoil was made of a platinum coil spring, and consisted of firm and flexible segments. The firm segment functioned as an anchor and the flexible segment was well compacted to occlude the arteries. No Dacron fiber was attached. Seventy-one new microcoils were placed via microcatheters in 28 visceral arteries of 17 patients. Two other types of microcoils with Dacron fibers were used together in 8 arteries.

RESULTS

Sixty-nine new microcoils were placed and compacted successfully. Two coils were misplaced; one was retrieved and the other was left in the migrated artery, which remained patent 5 months later. All 28 arteries were occluded, and the goals of intervention were achieved successfully in all 17 cases.

CONCLUSION

The new microcoils anchored and compacted well in the arteries. The clinical feasibility of this coil design was confirmed. The additional use of other types of microcoils with Dacron fiber was necessary to obtain rapid occlusion in some cases.