Lecture 6- Book material (exam 3)

Question 1

Seldinger Technique:
* What is it used for?
* It involves the use of what?
* What is the mc way to access vascular? What is used as a landmark?
* What is given at the beginning of the procedure? Where?

Answer 1

• is used on a daily basis for percutaneous arterial catheterization. It involves the use of a needle, guidewire, and catheter.
• Vascular access is most commonly attained via the common femoral artery.
• Using the femoral head and inguinal ligament as a landmark under fluoroscopy, an appropriate skin entry site in chosen.
• Local anesthetic is given using 1% or 2% lidocaine at the beginning of the procedure in an intradermal and subcutaneous fashion. Aspiration prior to injection is used to avoid intravascular injection of lidocaine.

Question 2

What are the steps of seldinger technique? (5)

Answer 2

• A superficial skin nick is made directly over the arterial pulse. Using a blunt hemostat, subcutaneous dissection is performed. While palpating the femoral artery pulse, an 18 gauge needle is advanced in a controlled fashion at a 45 degree angle toward the femoral head. Brisk pulsatile bright red blood is encountered upon a successful arterial puncture.
• A 0.035 inch Bentson wire is advanced through the needle into the common femoral artery and abdominal aorta under fluoroscopic guidance.
• While holding pressure at the arteriotomy site, the needle is slowly removed and the wire is cleaned with wet gauze.
• A sheath or catheter is then advanced over the guidewire into the common femoral artery in a smooth fashion.
• The guidewire and sheath inner stiffener is removed and the sheath is flushed with normal saline. The sheath can then be used to exchange for different types, sizes, and length of catheters. Catheters are always advanced over a guidewire to prevent arterial injury.

Question 3

What type of needle is used for vascular catheterization? Some practitioners may decide to use what?

Answer 3

• A single wall needle with a sharp beveled edge for vascular catheterization
• Some practitioners prefer a 21 gauge needle and thinner 0.018 inch wire to access the common femoral artery. This can then be upsized to a 0.035 inch Bentson wire using a 5 French (Fr) sheath (1 Fr = 1/3 mm).

Question 4

What are the complications of seldinger technique? (3)

Answer 4

• Retroperitoneal hemorrhage if the arterial access is too high.
• Low arterial access into the superficial or deep femoral artery increasing the chance of arterial thrombosis, pseudoaneurysm, or arteriovenous fistula formation.
• Arterial injury, dissection, or occlusion. The Seldinger technique is also used for central venous access.

Question 5

What are guidewires used for?
* How do they differ?
* The exterior may be made up of what?
* What are the diameters?

Answer 5

• Guidewires, as the name implies, are used primarily to direct catheters into specific locations within a blood vessel, cavity, or organ.
• Guidewires mainly differ by length, diameter, stiffness, tip characteristics, and pliability.
• The exterior may be hydrophobic or hydrophilic.
• Standard guide wires come in 0.035 or 0.038­inch diameters.

Question 6

Catheters:
* What types are there? (2)
* How do they differ?

Answer 6

• There are angiographic and drainage catheters
• Angiographic catheters differ by pliability, external coating, and tip contour.

Question 7

What are these?

Answer 7

Pigtail catheter with inner metallic component.

Question 8

What do these show?

Answer 8

High­flow catheters, including pigtail and modified pigtail.

Question 9

What are these?

Answer 9

• Top row, from left to right: basic straight angiographic catheters—spinal, cobra, headhunter, and angled shapes.
• Bottom row, from left to right: basic reverse curve catheters—Bookstein, Simmons (sidewinder), Shetty, and visceral hook.

Question 10

Sheaths:
* When are these placed?
* What do they provide and do?
* What are they composed of?

Answer 10

• Sheaths are placed when lengthy vascular interventions and multiple catheter/guidewire exchanges are anticipated.
• They provide a safe passage of guidewires and catheters into the artery.
• Sheaths can also be placed to control persistent oozing or hematoma at the arterial access site.
• Sheaths are composed of an inner stiffener and outer thin wall.

Question 11

Sheaths:
* The inner stiffener is present to do what?
* What is also present at the proximal end? Why?
* What is available for injection of contrast?
* Some have a peel­away outer component that can be what?

Answer 11

• The inner stiffener is present to prevent buckling during insertion and is removed once access has been established.
• They also have a valve at the proximal end to prevent free backflow.
• A side arm is available for injection of contrast.
• Some have a peel away outer component that can be easily removed once a more stable access to a vein, organ, or cavity has been established.

Question 12

What is this?

Answer 12

Vascular access catheter consisting of sheath with a side arm and inner dilator

Question 13

balloons:
* What are they used for?
* What is the procedure called?
* Using an inflation device, the balloon can be inflated or deflated to a measurable pressure using what?
* What does the balloon cause?
* Balloons differ by what?
* Balloons are also used to expand what? Why?

Answer 13

• Inflatable balloons are used to open stenosis within vessels, or other parts of the body such as the urinary tract, and biliary systems.
• The procedure is called percutaneous transluminal balloon angioplasty (PTA).
• Using an inflation device, the balloon can be inflated or deflated to a measurable pressure using air, saline, or contrast.
• It causes a controlled stretch injury to the lumen, which then scars into place.
• Balloons differ by diameter, length, shape, burst pressure, surface, and pliability.
• Balloons are also used to expand stents placed within vessels and channels. They are inflated within the stent to achieve the desired lumen diameter and force the stent to appose the wall of the vessel or channel.

Question 14

Stents
* Are used for what?
* What are stents?
* What are the different types?

Answer 14

• Stents are used in a variety of procedures to maintain luminal patency within arteries, veins, bile ducts, bowel, urinary tract, and artificially created channels.
• Stents are tubular metallic cages that differ by length, longitudinal flexibility, elasticity or plasticity, radial force, composition, radiopacity, shortening with deployment, and compatibility with magnetic resonance imaging (MRI).
• There are self expanding, balloon expandable (Fig. 8.7), drug eluting, and covered stents.

Question 15

What does this show?

Answer 15

Balloon expandable stent placement to treat renal artery stenosis.

Question 16

Needles:
* Come in varying what?
* They can be used for what?
* The type of needle used depends on what?

Answer 16

• Needles come in varying lengths, diameters (gauges), and tips.
• They can be used to access vessels or organs, aspirate fluid from cavities, and biopsy masses.
• The type of needle used depends on the procedure being performed.

Question 17

What do one step needles consist of? What can they be used for?

Answer 17

• One step needles consist of an inner hollow metallic needle and outer thin sheath with side holes at the distal end.
• They can be used to drain or access fluid within the peritoneal or thoracic cavities.

Question 18

What is this?

Answer 18

One step needle also known as the Yueh needle.

Question 19

What type of needles are typically used for biopsies? How does it work

Answer 19

• Noncutting and cutting needles are typically used for biopsies.
• A small sample can be aspirated into the needle attached to syringe or automatically pulled into the needle via capillary action or manual aspiration.

Question 20

What is a two step needle used for? How does it work?

Answer 20

• A two step needle is used for soft tissue mass biopsies and typically consists of a slotted inner stylet that catches the specimen and spring loaded cutting outer cannula.
• The stylet is advanced into the biopsy target and the cutting outer cannula is manually fired. The outer cannula is then retracted to reveal the specimen within the slot.

Question 21

What is this?

Answer 21

Two step spring loaded biopsy needle with slotted inner stylet.

Question 22

• Hemodialysis catheter is placed in patients with what?
• What are the procedure contraindications?

Answer 22

• A hemodialysis catheter is placed in patients with acute renal failure needing urgent dialysis for electrolyte imbalance, fluid overload, uremia, etc. It is also used in patients with chronic renal failure as a bridge to arteriovenous fistula/graft creation or renal transplant.
• CI: Coagulopathy, thrombocytopenia, and inability to get central venous access.

Question 23

• What is the goal of dialysis catheter placement?
• What does the catheter have? What does each one do?

Answer 23

• The goal of dialysis catheter placement is to provide long term access for exchanging blood to and from a hemodialysis machine.
• The catheter has an arterial and venous lumen.
• The arterial lumen withdraws blood from the patient, and the venous lumen returns blood to the patient from the machine. The flow rates are typically between 200 and 500 mL/min.

Question 24

dialysis catheter placement

What is the overview of the procedure for hemodialysis catheter placement?

Answer 24

Question 25

What does this show?

Answer 25

Hemodialysis catheter
* The sheath is then peeled away while ensuring the catheter remains in place

Question 26

What are the complication of Hemodialysis catheter

Answer 26

• Hemorrhage
• Infection
• Thrombosis or injury of central vein
• Clotting or kinking of catheter

Question 27

Gastrostomy tube:
* What are the procedure indications?
* What are the procedure CI?

Answer 27

• Nutritional support in patients with stroke or esophageal obstruction, decompression of gastroenteric contents in patients with gastroparesis or gastric outlet obstruction, and diversion in cases of esophageal leaks.
• Absolute contraindications include inability to access stomach due to overlying colon, spleen, or liver, and uncorrectable coagulopathy. Relative contraindications include large ascites, gastric varices, distorted anatomy from prior surgery, or severe gastroesophageal reflux leading to aspiration of feedings.

Question 28

What si the procedure overview of gastrostomy?

Answer 28

The patient is placed in supine position. A nasogastric tube is placed under fluoroscopic guidance. An ultrasound is used to outline the liver border to avoid it during the tube placement. The left subcostal or epigastric region is prepped in sterile fashion, and 1 mg of glucagon is administered to reduce gastic peristalsis. The stomach is insuflated with air via the nasogastric tube until adequate gastric distension is achieved. A puncture site is chosen and infiltrated with lidocaine. A small incision is made and a large gauge needle is used to puncture the stomach. Confirmation of gastric placement is done with aspiration of air and contrast injection under fluoroscopic guidance . Gastropexy device is deployed to approximate the anterior gastric wall to the abdominal wall. A stiff wire is then looped into the stomach through the needle. The needle is removed and fascial dilaters are used to dilate the tract to accept a 12 Fr or large gastrostomy tube. The gastrostomy catheter is advanced into the stomach over the guidewire and the loop is formed in the stomach. Confirmation of placement is done with contrast injection under fluoroscopic guidance. The catheter is secured to the skin with prolene sutures and the site is dressed. The tube can be used for feeding in 24 hours if there are no signs of peritonitis, there are active bowel sounds, and gastric contents can be aspirated from the tube.

Question 29

What does this show?

Answer 29

gastrostomy catheter
* Percutaneous access of a gas distended stomach with a needle (left arrow).
* Notice opacification of the stomach rugal folds (right arrow) with contrast.

Question 30

What does this show?

Answer 30

Final image showing pigtail end of gastrostomy catheter in the stomach pylorus (arrow) as confirmed by contrast injection.

Question 31

What are the complications of gastrostomy catheter

Answer 31

Question 32

Port placement:
* What are the procedure indications?
* What are procedure contraindications?

Answer 32

• A port can be used for administration of chemotherapy, long- term antibiotics, and contrast for CT/MRI examinations. It can also be used for obtaining blood samples.
• Coagulopathy, thrombocytopenia, and inability to obtain central venous access.

Question 33

What is the procedure overview of port placement?

Answer 33

Question 34

What does this show?

Answer 34

Right internal jugular port with catheter tip (arrow) in the right atrium.

Question 35

Right internal jugular port complications?

Answer 35