Radiological placement of an arm mini-port system

Clinical History

Placement of a new port system in a patient with breast cancer after paravasation out of a chest-wall port reservoir with necrosis of the skin and muscles.

Imaging Findings

The patient was diagnosed with cancer in her right breast at the age of 46. She had a mastectomy, axillary dissection and post operative chemotherapy. A single pulmonary metastasis was detected 6 years later and for the scheduled chemotherapy a chest-wall port was implanted with a catheter in the left subclavian vein. After 6 of 12 chemotherapy cycles a paravasation occurred due to migration of the needle out of the port reservoir. The reservoir and the resulting skin and muscle necrosis around the reservoir had to be removed surgically. To provide a permanent venous access for the still upcoming chemotherapy it was then decided to implant a mini-port system at the left arm. We implanted a Cook titanium Mini Vital-Port proximal to the antecubital fossa subcutaneously into the left upper arm medially. After circumferential skin disinfection from the wrist up to the axilla the arm was fully draped except the distal part of the left lower arm. Phlebography (Fig. 1a) was performed through an intravenous catheter placed in a superficial vein of the hand. After local anesthesia the basilic vein was accessed under fluoroscopic guidance with a Cook Micropuncture Set. To prevent venous spasm local anesthesia was not injected around the vein to be punctured. A 0.46 mm wire (0.018 in.) was inserted and a 6 F peel-away sheath was introduced. Once the inner catheter was exchanged for a 5.2 F port silicone catheter (Fig. 2a), the latter was advanced the right atrium and the peel-away sheath was removed carefully without pulling the catheter back (Fig. 2b). The catheter was flushed with heparinized saline solution. Then preparations were made for the port implantation: 2-3 cm distally to the puncture site a 2.5 cm long transverse skin incision was made. From this incision the reservoir pocket was formed subcutaneously in distal direction using blunt dissection. Bleeding from subcutaneous vessels were stopped by electrocautery. Also a short subcutaneous tunnel was created between the port pocket and the puncture site which was incised for 3 mm. The silicone catheter was now pulled from the puncture site through the tunnel to the pocket in such a way until the distal tip was positioned in the proximal superior vena cava (SVC). The catheter was cut, connected to the port and secured by a sleeve (Fig. 2c). The port was then punctured with a non-coring needle and flushed to ensure normal function. Now the reservoir was placed in the subcutaneous pocket (Fig. 2d) without suture fixation. After subcutaneous suture (3-0 Dexone) the skin incisions were closed with 3-0 Prolene (Fig. 2e). Finally the reservoir was accessed through the skin and after injecting i.v. contrast medium perfect function was documented (Fig. 3 a,b). The patient did not receive prophylactic intravenous or oral antibiotics. The sutures were removed after 10 days and the arm port has been used now for about 6 month without any problems.

Discussion

Patients with cancer require a reliable venous access for blood sampling and for infusion of parenteral nutrition, chemotherapy, medication and blood products. Considering the frequency of venous access and the usually poor status of the patient’s veins the repeated venipuncture is a nightmare for both, patient and physician. Traditionally, surgically implanted chest-wall ports were chosen to provide a long term peripheral venous access system. In recent years subcutaneously implanted arm ports have gained increasing acceptance by referring physicians and their patients. The implantation can be performed in a vascular/interventional suite under local anesthesia on an outpatient basis (Fig. 4a). The minor percutaneous procedure takes between 30 and 45 minutes. Long-term follow up studies show that complication rates including venous thrombosis and local and catheter infection are comparable to those after surgical chest-wall implantation. Severe complications, however, like pneumothorax, air embolism and central vascular injuries are missing. The benefits and risks of a venous access system must be weighted and the ideal device for each patient has to be chosen individually. Due to the smaller port reservoirs and catheter diameter arm ports have a limited flow rate. Also no dual reservoirs for simultamous infusion of different solutions can be placed in the arm due to large size of such a device. After removal of the chest-wall port the newly implanted arm port was the only possibility for our patient to have a permanent reliable venous access for her ongoing chemotherapy.

Differential Diagnosis List

Final Diagnosis

Radiologically guided percutaneous placement of an arm mini-port system

URL:	https://eurorad.org/case/845
DOI:	10.1594/EURORAD/CASE.845
ISSN:	1563-4086