Miniature Pump for Treatment of Refractory Ascites Based on Local Magnetic Actuation

This paper presents the design, fabrication, and experimental validation of a novel low-cost implantable pump for the treatment of refractory ascites (RA) based on local magnetic actuation (LMA). A reciprocating positive displacement pump displaces liquid unidirectionally through magnetic coupling with a magnetic controller placed on the outside of the patient's body. The proposed solution is intuitive to use given an alignment algorithm that exploits externally placed magnetic field sensors (MFS). The implantable device has a catheter-like shape, is electronic free (no on-board battery), has low fabrication cost (<8 USD), and is able to generate a flow-rate of 3.65 L/h while effectively pumping fluids with various viscosity (1–5.5 cP). RA is commonly treated via costly paracentesis or invasive surgical placement of a transjugular portosystemic shunt (TIPS). The proposed solution can be implanted with minimally invasive techniques and can be used on a daily basis to drain a set amount of liquid, without requiring recurrent hospital visits.

Extravascular Revascularization of a Chronic Total Occlusion Using the Dual Bull’s-Eye Technique

Purpose: To describe the dual bull’s-eye technique to achieve successful extravascular revascularization of an occlusion after vessel perforation when the antegrade and retrograde catheters are too far apart for salvage with a reentry catheter. Technique: The dual bull’s-eye technique, which is an adaptation of the “gun-sight” method for transjugular portosystemic shunt procedures, is demonstrated in a popliteal artery occlusion in which multiple recanalization attempts have produced vessel perforation. Via antegrade femoral and retrograde anterior tibial artery accesses, 10-mm Amplatz GooseNeck snares were advanced in plane from each access to rendezvous in the popliteal fossa to obtain through-and-through wire access. A 15-cm Chiba needle was advanced percutaneously in plane through both snares, and a hydrophilic guidewire was maneuvered across an extravascular tract parallel to the popliteal artery. The tract was carefully predilated, and a 5×100-mm Viabahn stent-graft was deployed across the extravascular tract. Conclusion: Owing to potential complications (limited patency, injury to adjacent structures) and only single-case use, this new technique should be considered a bailout strategy exclusively employed for limb salvage when traditional methods have failed and there are no viable surgical options.