Interventional Radiology for the Hospitalist/Primary Care (Page, 10/13/2021)

Many thanks to Dr. Alex Page (Redwood Radiology Group) for a great presentation this week titled Interventional Radiology for the PCP/Hospitalist. It seems IR docs can do just about anything these days-- certainly with all kinds of tricks up their sleeves. But what should I know as a primary care doc? Who can I refer? What can patients expect? And how should I manage common post-IR procedural issues?

A recording of his presentation is available here: https://youtu.be/9wmAL7s9KAQ

For clarification, interventional radiology is defined as minimally invasive image-guided treatment of medical conditions that once required surgery, like surgery only MAGIC. ☺

IR physicians work with practically every body system (minus brain, skin and heart. Their work can be broken into two broad categories:

• Endovascular procedures: including vascular access (vein, artery, lymphatics) and catheterization (stenting, embolization, angioplasty, venoplasty)

and 

• Percutaneous interventions: using CT/ultrasound to advance a needle to put in drain, biopsy lesions, ablate tumors/growths, etc

"We can almost get anywhere" (danger zones where your local IR doc may take a moment: mediastinum, around heart, deep abdomen)

For detailed ideas of possible IR procedures, see the image below from Society of Interventional Radiology for the wide scope of IR docs

www.sirweb.org

Vascular Access

IR can place a range of central lines, HD catheters, and ports

Central lines (for abx/meds, not the same as PICC; locally our PICC nurses place these)

**Central line Pearl: If you are concerned that patient is heading toward ESRD and possible HD, PICC lines can ruin peripheral veins and make it hard for vascular surgeons to make AV fistula, so consider opting for a central line in that circumstance

HD catheters (large bore, two lumens)

**Pearl: Right after being placed, bleeding from tunneled catheters can only be in two places: along the tract where catheter is tunneled, the vein around the catheter at the IJ site. If it has been placed for some time, pressure should be held at the neck only because bleeding only coming from the IJ site

**Pearl: Noe that the Cuff (made of dacron) is supposed to be inside tract, body scars down on it to prevent CLABSI. If the cuff is EVER visible, catheter needs to be exchanged

Ports: if you look closely can see the image of a C/T on the port. If it is right side up, you should see it on the x-ray. In addition, the tip should be right at the top of the  R atrium (approximately two vertebral bodies below the carina, one vertebral body below bronchus intermedius)

Of note, the tip of Catheter/port does move based on patient position (when breathing out, tip will be at lowest position). If too deep, can cause arrhythmia. If too shallow (way up in SVC), can cause stenosis and create access issue. Fine balance to have in right spot

Ports can be implanted for 1-2 years, should be able to remove without difficulty

Do not use HD tunneled catheter for vascular access unless emergent

Ports can be easily accessed (usually by RN protocol); has to be accessed with a Huber needle (slight curve with hole on the side to prevent coring the membrane from the port), use sterile technique, pin down with fingers (has 3 little bumps),

Veins used for port/cath: IJ (nicest easiest, safest)>> EJ>> subclavian (can be done with landmarks)>> femoral (higher infection incidence, less clean)>>IVC>> hepatic veins

Fistulas and Grafts

Fistula is an abnormal connection between artery and vein, created by surgeons, can use either a native vein (i.e. fistula), e.g. brachial artery connected to cephalic vein

Takes time for vein to mature (months), more durable, last longer

If fistula not an option, they use a graft: firm loop use PTFE to create a circuit, can be used much sooner, don't last as long (because foreign material), anastomosis

Can have venous outlet stenosis, can do angioplasty to save fistula

Should feel a "thrill" instead of a pulse

Possible complications:

• Patients with MAJOR  upper extremity swelling= central stenosis of the fistula, indication for IR referral to help open
• Prolonged bleeding can also be caused by central stenosis, indication for IR referral
• Infection; native fistula doesn't commonly get infected (except thrombophlebitis), graft infection is major issue (needs to be removed): erythema pain, fever
• Steal syndrome: claudication, painful hand, especially during HD

Abscess Drains

Diverticular abscess most common. Additional abscess include: appendiceal abscess, hepatic abscess, pancreatic pseudocyst, cholecystitis, percutaneous nephrostomy tubes, tubo-ovarian abscess

Normal sequence for drains

IR places drain--> Bulb suction (flush until minimal clear output)--> Abscessogram vs. CT vs. "just pull"

Major problem: fistula

Repeat abscessogram q2 weeks until fistula closes

Can work with GI if place a wire in fistula to clip diverticula

Fistula= surgery (colectomy in setting of diverticulitis)

How much to flush:  many IR docs use 10ml flush (can do less if small cavity)

Abscessogram: fluoroscopic (moving x-ray, live x-ray used to do procedure), inject with contrast--> look for pocket where abscess was (when contrast injected, if big and distended, means pocket is still there). Can also visualized presence of fistula. Repeat until  pocket/fistula disappears

Biopsies

lung, liver, bone, lymph notes

CT and/or ultrasound (if a hollow viscous containing air, cannot see through it on ultrasound)

Lung biopsy is the most dangerous (20% of small pneumothorax, 5% chance for chest tube due to air leak, hemoptysis, air embolism=death)

Solid organ biopsies are risky because of bleeding (kidney, liver): if sending a patient for liver/kidney, SBP must be <150

INR and platelets: varies by procedure (HIGH vs. Low risk bleeding procedure)

platelets >50, INR <1.5

High risk bleeding procedures

Low risk bleeding procedure (e.g. port, tunnelle lines paracentesis, bone marrow bx): platelets can be quite low, BM <20

There is a document from SIR which dictates INR/platelet counts based on procedure

Kyphoplasty

can lead to immediate pain relief

Indications: osteoporosis, acute/subacute vertebral body fracture (<30 days) with midline pain/tenderness, cannot do too high (high thoracic, cervical spine)

Advance needle into vertebral body (through pedicle, stay lateral of medial aspect of the pedicle to avoid the spinal canal), inflate a meeting, put in cement, fill the anterior aspect of the vertebral body and stops fracture fragments from moving and can signficiantly improve pain

Risks: fracture adjacent vertebral body (because cemented body is so much stronger than natural bodies), cement migration

And finally, information to have ready for IR consultation

1) Desired procedure

2)  Indication for procedure

2) urgency of procedure

3) anticoagulation/platelets

4) NPO status

Who to call?

SSSRH scheduler: 707-576-4278

SRMH scheduler: 707-525-5269

IR on call: 707-571-7007