1. Digital subtraction angiography (DSA) is an X-ray procedure that involves acquiring digital fluoroscopic images before and after injecting contrast dye and digitally subtracting the pre-contrast images from the post-contrast images, clearly showing blood vessels. 2. Proper pre-procedural preparation includes obtaining consent, checking vitals, performing imaging like CTA, and ensuring proper anticoagulation. Instruments used include access needles, guidewires, and dilators to facilitate catheter entry into vessels. 3. Strict aseptic techniques like appropriate skin antisepsis, sterile draping, and instrument sterilization are followed to prevent infections at the puncture site.

1. Standards Of Pre-procedural
Steps For DSA
Dr Sumeet Singh
Senior Resident Neurology
GMC, Kota

2. Introduction
• Digital subtraction angiography (DSA) is an X-ray procedure
• Acquisition of digital fluoroscopic images combined with injection of
contrast material
• Real-time subtraction of pre and postcontrast images
• The Portuguese neurologist Egas Moniz,( Nobel Prize winner 1949), in
1927developed the technique of contrast x-ray cerebral angiography
to diagnose diseases
• The idea of subtraction images was first proposed by the Dutch
radiologist Ziedses des Plantes in the 1935
Raja SM, Othman SA, Roslan RM. A Short Review on the Imaging Technology in Radiation Therapy. e-
Jurnal Penyelidikan dan Inovasi. 2023 Apr 30:108-22.

3. Introduction cont…
• A team of neurointerventionist, anesthesiologist, radiographer, nurses
do the procedure.
• Iodine-containing contrast medium is injected directly into an artery
or vein.
• A plastic tube (catheter) is passed from the groin or over the arm to
the carotid arteries
• Contrast medium is then injected via the catheter and subsequently
images of the blood vessels are taken
Scollan ME, Azimov N, Garzon MC, Tulin‐Silver S. An overview of interventional radiology techniques for
the diagnosis and management of vascular anomalies: Part 1. Pediatric dermatology. 2023 Mar;40(2):242-
9.

4. • The scout film shows the structural details of the adjacent soft tissue.
• Angiogram film shows exactly the same anatomic details, if the
patient does not move, plus the opacified blood vessels.
• If all the information in the scout film could be subtracted from the
angiogram film, only the opacified vessel pattern remains visible.

5. Pre procedural preparation
1.Routine pre-procedure workup:
• (a)History and physical -Prior surgery(vascular), vascular event,
Diabetes ,Medications, Prior imaging
• (b)Neurological exam- pulse distal to the site of access on both sides
• (c) Imaging(CTA of head, neck vessels and arch of aorta)
• (d) Blood work (CBC, Cr, PT, PTT)
• (e) EKG
• (f) Anesthesia evaluation, if needed
Gruschwitz P, Hartung V, Kleefeldt F, Peter D, Lichthardt S, Huflage H, Grunz JP, Augustin AM, Ergün S, Bley
TA, Petritsch B. Continuous extracorporeal femoral perfusion model for intravascular ultrasound, computed
tomography and digital subtraction angiography. Plos one. 2023 May 23;18(5):e0285810.

6. 2.Informed Consent :
• Taken by the doctor doing the procedure or trained staff.
• Patient information
1. Details of diagnosis and prognosis if left untreated
2. Options for treatment or management of the condition, including the
option not to treat.
3. Benefits and probabilities of success
4. Frequently occurring/serious risks involved
5. Reminder that patients are entitled to change their minds about a decision
at any time or take a second opinion

7. • Consent for any medical emergencies:
• Provide medical treatment in order to save life or avoid significant
deterioration
• After recovery inform patient what and why the procedure done
Ganaie HA, Sanaie BA, Maqsood S, Raina A, Shaheen F, Asimi R, Hilal S, Zaffar DS. Utility and
Safety of Digital Subtraction Angiography in Management of Cerebrovascular Diseases. European
Journal of Molecular & Clinical Medicine.;9(07):2022.

8. 4.Foley catheter
• (a) Insert in the patient’s private room or pre-op area for awake
patients
• (b) Insert in the angiography suite, after induction of anaesthesia, for
asleep patients
5. NPO after midnight or 6 h prior to the procedure except for
medications.
6. Place thigh-high sequential compression device (SCD) sleeves on
both legs for deep venous thrombosis prophylaxis.

9. • Safety Consideration
• Radiation Exposure
• Fluoroscopy only when needed
• Use pulsed Fluoro modes(Use < 10 pulses per second )
• Wear lead aprons , thyroid shields, leaded glasses, and radiation badges.
• Ergonomic Considerations
• Degenerative disease of neck and spine needs to be taken care
• Proper positioning of the patient table
• Careful positioning of the controls and monitor
Shaban S, Huasen B, Haridas A, Killingsworth M, Worthington J, Jabbour P, Bhaskar SM. Digital
subtraction angiography in cerebrovascular disease: current practice and perspectives on diagnosis,
acute treatment and prognosis. Acta Neurologica Belgica. 2021 Sep 22:1-8.

10. Premedication:
(a)Continue antiplatelet therapy.
(b) Protection from nephrotoxicity with creatinine ≥1.5 mg/dL:
• PO hydration (water, 500 mL prior to the procedure and 2000 mL after the
procedure).
• IV hydration with 0.9% sodium chloride .
• Acetylcysteine 600 mg (3 mL) PO BID on the day before and the day of the
procedure .
(c) Protection against anaphylaxis for patients with history of contrast
allergy:
• Prednisone 50 mg PO (or hydrocortisone 200 mg IV) 13, 7, and 1 h prior to
contrast injection
• Diphenhydramine 50 mg IV, IM, or PO 1 h prior to contrast injection.
• Steroids(if needed)should be given at least 6 h prior to the procedure

11. • D)Warfarin- Stop 3 days prior ,Check INR previous day (INR <1.5)
• E)Antidiabetic medications
• Insulin: Reduce by 50% with 5D infusion with RBS monitoring
• Metformin: stop 48 hrs prior , Check RFT before restarting
• Others: stop on the day of procedure, restart on taking food
Harrigan MR, Deveikis JP, Harrigan MR, Deveikis JP. General considerations for neurointerventional
procedures. Handbook of Cerebrovascular Disease and Neurointerventional Technique. 2018:167-246.

12. Steps of handwashing
Step 1: Wet Hands
• Wet your hands and apply
enough liquid soap to create a
good lather.
• The temperature of the water
should be between 35ºC and
45ºC.
Step 2: Rub Palms Together
• Rub your hands palm to palm in
circular motions.
• Rotate clockwise and
anticlockwise
HAO M, HE J, ZENG Y, HAN W, SAI A, YAMAUCHI T. A comprehensive assessment of hand
washing: knowledge, attitudes and practices (KAP) and hand-washing behaviors among
primary school students in northeast China. Sanitation Value Chain. 2022;6(1):13-22.

13. Step 3: Rub the Back of Hands
• With your fingers linked
through the other hand, use
your right palm to rub the back
of your left hand. Then swap
Step 4: Interlink Your Fingers
• Link your fingers together,
facing each other, into clasped
hands.
• Then rub your palms and
fingers together.

14. Step 5: Cup Your Fingers
• Cup your fingers together, with your
right hand over and your left hand
under.
• With your fingers interlocked, rub the
backs of them against your palms.
Then swap
Step 6: Clean the Thumbs
• Enclose your right hand around your
left thumb and rub as you rotate it, then
swap.

15. Step 7: Rub Palms with Your Fingers
• Rub your fingers over your left palm in a circular
motion, then swap.
Step 8: clean your wrists: Extend the scrubbing to
your wrists and lower arms, especially if they've
been exposed to contaminants
Step 9:Rinse Thoroughly
Step 10:Avoid Touching the Tap
Step 11:Dry Your Hands with sterile towel or air
dryer
Step 12:Dispose of Towel Properly
Step 13: Use of hand sanitizers

18. Part preparation and cleaning of puncture site
Shaving: Hair around the puncture site should be shaved to ensure
proper adhesion of sterile drapes and minimize infection risk.
Patient Positioning: Ensure that the patient is in the appropriate
position(supine) for the puncture.
Sterile Field: Establish a sterile field around the puncture site to
minimize the risk of contamination.
Gather Supplies: Assemble all the necessary supplies, including an
appropriate antiseptic solution, sterile gauze, and sterile drapes.
Skin Antisepsis:
• Use an appropriate antiseptic solution to cleanse the skin at the puncture site.
• Common choices include chlorhexidine or iodine-based solutions
Singh DK, Yadav K, Singh AK, Sinha K, Kaif M, Kumar R, Chand VK. Digital Subtraction Angiography of
Cerebral Vessels: Basic Technique. Neurology India. 2023 Jan 1;71(1):31.

19. Pre-Cleanse Assessment:
1.Examine the patient's skin for any visible contaminants, such as
dirt, debris, or organic matter.
2.If present, remove these contaminants with a gentle, sterile saline
solution.
Antisepsis Application:
1.Apply the prepared antiseptic solution to the surgical site using
aseptic technique.
2.Start at the center and work outward in a concentric manner.
3.Use sterile gauze or swabs soaked in the antiseptic to scrub the
area for the recommended duration, usually 2-5 minutes,
depending on the product.

20. Draping
• Start at the near side (closest to your body) then place the drapes at
either end and then at the far side.
• If a drape needs adjustment, only move away from sterile area, not
towards or over it.
• When placing the clip grasp sufficient, but not an excessive amount,
of skin .
Gao C, Zhu J, Bai Z, Lin Z, Guo J. Novel ramie fabric-based draping evaporator for tunable water supply and highly efficient
solar desalination. ACS Applied Materials & Interfaces. 2021 Feb 2;13(6):7200-7.

26. Instruments and tools for DSA
Access Needle
ONE PIECE
• Sharp beveled tip
• Guidewire introduced directly through it
• Both arterial and venous access
TWO PIECE
• Blunt tip with sharp stylus
• Less vascular injury with the blunt tip
• Guide wire inserted after removing the stylet
• Usually for arterial puncture
MC needle Size – 19/18 G in diameter and 21/4 - 5
inches in length
YAJUN N. A Analysis of the Practice Effectiveness of Care Management in Digital Subtraction Angiography Composite Operating Rooms.
Archives of Clinical Psychiatry. 2022;49(6).

27. Micro puncture Access Systems
• Small access needle – made
bigger with plastic introducer
• 21 G needle for access
• Guide wire
• 4F or 5F Dilator
Singh DK, Yadav K, Singh AK, Sinha K, Kaif M, Kumar R, Chand VK. Digital Subtraction Angiography of Cerebral
Vessels: Basic Technique. Neurology India. 2023 Jan 1;71(1):31.

28. Dilator
• Plastic catheter
• Purpose: Spread the soft tissues and
vessel wall to facilitate catheter entry
• Sequential dilatation to prevent trauma
• Usually 18G access needle uses 5F
initially
• >50% diameter of the vessel diameter –
obviates manual compression

29. SHEATHS
• Open at one end with capped
hemostatic valve in the other
• Atraumatic vascular access
• Simplify catheter exchange through
a single access
• Maintain guidewire position
• Prevent bleeding
• Size 4-9 F
Summers, M.R., Lavigne, P.M. and Mahoney, P.D., 2022. Completion peripheral angiography in single‐access, Impella‐assisted, high‐risk PCI:
using a buddy microcatheter sheath after MANTA closure for imaging and potential bailout. Catheterization and Cardiovascular
Interventions, 99(6), pp.1778-1783.

30. Guidewires:
• The guidewire should have a thickness
that matches or is slightly smaller than the
size of the tip of the catheter or device
that it guides.
• It comprises a central stiff core, which
provides stability, and an outer wrap
wound around it
• The guidewire is designed to withstand
damage
• To enhance safety, a small safety wire is
incorporated within the guidewire,
securely attached at both ends.
• The safety wire prevents the guidewire
from unwinding if it happens to break
during use.
• Average Length : 145-160cm( Exchange length

31. Types of guidewires:
• Stiff guidewire – introducing catheter and
devices
• Flexible : negotiating tortuous and diseased
vessels
• Movable core guidewire – adjust flexibility
• Mandril Guidewire : Only wrapped at the tip-
micro guidewire and extra rigid large
diameter guidewire
• Tip Deflecting guidewire : manipulate the
radius of tip
• Hydrophilic coated guide wire
• Coated central core
• Reduces friction
• Needs to be moist always

32. Diagnostic Catheter :
• Made of polyurethane, polyethylene, Teflon, or nylon
• Catheters vary based on their intended use
• Non selective aortography – Thick walled with pig tail tip , multiple side
holes
• Selective catheter : Thin walled with tapered tip , single end hole and
metal /plastic strand BRAID tip
• Length – 50 -125 cm
• Size :4F-6F
Singh DK, Yadav K, Singh AK, Sinha K, Kaif M, Kumar R, Chand VK. Digital Subtraction Angiography of Cerebral
Vessels: Basic Technique. Neurology India. 2023 Jan 1;71(1):31.

33. Types :
• Benston and floppy tipped wires- for standard access
• Hydrophilic wires- for tortuous and diseased vessels
• Extra stiff wires(Amplatz)- insertion of larger devices or within long tracts
• Exchange wires- exchange of long angiographic catheters or devices or
remote distance from access
• Tapered wires(TAD wires)- for placement of devices into sensitive
territories
• Low profile steerable wires- used in microcatheters for selective
catheterization.

34. • Based on shape : pigtail , cobra, hockey stick
Designer :
• AMPLATZ catheter
• HEADHUNTER – H1,H3,H1H
• SIDEWINDER – SIM1, SIM2, SIM3, SIM4
• NWTON – HN 3, HN 4
• BENTSON, MANI – JB 1, JB 2, JB 3, MAN, CK 1
• SHEPARD HOOK – SHK 0.8, SHK 1.0, RDC 1, RDC
• COBRA – C 1, C 2, C 3, RC 1, RC 2, RC 3, USL 2

35. Luer lock syringe:
• Luer lock syringes have a threaded
tip
• For secure and leak-resistant
connection with various
attachments, such as needles,
catheters, or extension sets.
• The threaded design prevents
accidental disconnection during
use
• Reduces the risk of medication
leakage(contrast) and needlestick
injuries

36. Three way stop cock:
• A three-way stopcock typically has
three ports or openings that allow
for the connection of multiple
medical tubing or devices
simultaneously.
• They provide a convenient and
controlled way to manage the flow
of fluids and medications

37. • All the tools and instruments are
opened from their respective
packings with no touch technique
• They are assembled on sterile
platform
• Instruments are checked for their
patency with heparinised solution.
• NS is heparinized with 10,000 units of
heparin per liter of saline for flushing
and irrigation
Bhave VM, Stone LE, Rennert RC, Steinberg JA. Complementary tools in cerebral bypass
surgery. World Neurosurgery. 2022 Jul 1;163:50-9.

39. Contrast:
• Should have excellent radioopacity
• Good mixing with blood
• Easy to use, inexpensive and does not harm the
patient
• Ionic monomer-diatrizoate, iothalamate
• Nonionic monomer-ioppamidol, iohexol, ioversol,
ioxilan, iopramide.
• Ionic dimer- ioxaglate
• Nonionic dimer-iodixanol.
• Patients with normal renal function can tolerate as
much as 400–800 mL of Omnipaque , 300 mg /mL,
without adverse effects
• For patients with renal insufficiency use
Iodixanol(270 mg /mL)
Chandrashekar A, Shivakumar N, Lapolla P, Handa A, Grau V, Lee R. A deep learning approach to generate
contrast-enhanced computerised tomography angiograms without the use of intravenous contrast agents.
European Heart Journal. 2020 Nov;41(Supplement_2):ehaa946-0156.

40. Allergic reaction to contrast:
• Patients should be tested for any adverse reaction to contrast agents
• 20 to 50 microlitre of a 1:10 dilution of contrast with NS is injected
intradermally to make 3-5mm papule
• Test should be done 48-72 hours before the procedure
• Reading is done at 20 min and 72 hours for increase in size of wheal
for >3mm and erythema.
• If found allergic patient should be given-
• Prednisone 50 mg 1 hour prior to procedure
• Cimetidine 300mg iv on arrival to cathlab
• Diphenydramine, 50mg iv on arrival to cathlab

41. Contrast Induced Renal Failure:
Mostly in patients with DM, preexisting renal
failure(creatinine>1.5mg/dl)
Management :
• Hydration with D5 12 hour before and 12 hour post procedure
• Sodium bicarbonate-154mmol/L at 3ml/kg/h prior to procedure, then
1ml/kg/h for 6 hours after the procedure
• N-acetylcysteine- 1200 mg orally every 12hour starting 24 hour before the
procedure.

42. Radiation Safety
Patient Radiation Exposure:
• Radiation exposure to patients should be
minimized
• Limiting fluoroscopy time.
• Limit the pulse rate for fluoroscopy
• Do only the angiographic runs that are
needed.
• Use one 3D acquisition instead of six different
oblique runs
• Use overhead and table-side shielding to
protect body parts not being studied.
Doyen B, Vlerick P, Soenens G, Vermassen F, Van Herzeele I. Team perception of the radiation safety climate in the
hybrid angiography suite: A cross-sectional study. International Journal of Surgery. 2020 May 1;77:48-56.

43. Staff Radiation Exposure:
• Moveable, ceiling-mounted clear lead glass shields can be draped
with sterile plastic and positioned over the patient protecting the
patient’s lower body and the operator from radiation exposure.
• Rolling floor-mounted X-ray shields should be available to shield
anesthesia or other personnel.
• Lead aprons should provide at least 0.5 mm lead equivalent thickness
• Thyroid shields and lead glasses
• Lead apron has front cover, leaded skirt, arm and shoulder cover and
belt.
• Lead aprons can attenuate over 90% of 80 kVp radiation

44. • Pregnant staff members:
• The NCRP-recommended maximum gestational radiation exposure is 5 mSv
per gestational period, or 0.5 mSv per month
• Wear an apron with 1.0 mm lead equivalent thickness
• Wear wraparound aprons to cover front and back
• Pregnant staff members should wear two radiation badges, with one under
the apron to monitor fetal dose

45. Advances in Lead Apron Technology:
• Zero-Gravity- a ceiling-tethered apron, reduces the load of
the lead while confining the doctor to an area in the OR near
the bed.
• Provides enhanced head protection
• StemRad MD– an exoskeleton-based apron which reduces
the load of shielding from the wearer while allowing
movement around the OR
• Also providing head protection in the form of a visor.
• Cost 1000-1500 US Dollars.

47. Radiation monitoring batch
• For Personal radiation monitoring
• Worn inside lead apron
• These batches are passive dosimeters, do not
actively measure radiation but absorb it, usually
through special materials like film or
thermoluminescent detectors
• A badge consists of 3 TLD discs
• They are collected and assessed periodically
(e.g., monthly or quarterly)
• Read by TLD reader which is controlled by PC
and a software
• Personnel doses should not exceed 100 mSv in
5 year or 30 mSv in 1 year.

49. Conclusion
• All patients should be evaluated in detail and should have a justifiable reason to
go for DSA
• Serum creatinine should be <1.5 mg/dl and platelets >50K before the procedure
• Detailed Written and informed consent should be taken
• Patients should be NPO for at least 6 hours before the procedure
• Strict asepsis should be maintained while shaving and cleaning the puncture site
and in the Cath lab
• All instruments and tools should be handled with care and flushed with
heparinised solution.
• Patients should be checked for contrast allergy
• Radiation safety should be followed strictly with the use of protective shields ,
aprons and radiation monitoring batches.

50. References
• Handbook of Cerebrovascular Disease and Neurointerventional Technique Mark R. Harrigan John P. Deveikis
• Continuum journal.
• Raja SM, Othman SA, Roslan RM. A Short Review on the Imaging Technology in Radiation Therapy. e-Jurnal
Penyelidikan dan Inovasi. 2023 Apr 30:108-22
• Harrigan MR, Deveikis JP, Harrigan MR, Deveikis JP. General considerations for neurointerventional
procedures. Handbook of Cerebrovascular Disease and Neurointerventional Technique. 2018:167-246.
• Doyen B, Vlerick P, Soenens G, Vermassen F, Van Herzeele I. Team perception of the radiation safety climate in
the hybrid angiography suite: A cross-sectional study. International Journal of Surgery. 2020 May 1;77:48-56.
• Singh DK, Yadav K, Singh AK, Sinha K, Kaif M, Kumar R, Chand VK. Digital Subtraction Angiography of
Cerebral Vessels: Basic Technique. Neurology India. 2023 Jan 1;71(1):31.
• Summers, M.R., Lavigne, P.M. and Mahoney, P.D., 2022. Completion peripheral angiography in single‐access,
Impella‐assisted, high‐risk PCI: using a buddy microcatheter sheath after MANTA closure for imaging and
potential bailout. Catheterization and Cardiovascular Interventions, 99(6), pp.1778-1783.

51. Thank you