Complicatons in Intervention

8/9/2019 Complicatons in Intervention

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Complications in Radiology and

intervention Radiology


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Barium studies

Barium is an inert substance and is

incapable of triggering a reaction. salt is insoluble in waterso is not

absorbed through the intestinal mucosa.

This makes this salt nontoxic and safe forhuman use.


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Barium studies

Incidence of complication is 4.17%

Hypersentivity reaction

Impacton Perforation

Aspiration

Intestinal obstruction

Failure of ileostomy/colostomy closure


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Hypersensitivity reactions

Additives to provide properties of the

product.

Generally a well-kept secret

- carboxymethylcellulose

Aluminum hydroxide gel, simethiconePolyxethylene monooleate silica,

artificial sweeteners/flavors.


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Impaction


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Prevention of Barium Impaction

2 before - low-residue diet and fluids to ensure

adequate hydration. Day of the examination - patient should drink

plenty of clear fluids

Laxatives and Cleansing enemas.


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Prevention of Barium Impaction

75 percent barium - evacuated from the

rectum with the patient prone

Cannula is left in place for 10 minutes toallow further drainage of the barium.

Patient is encouraged to evacuate his or

her bowels into the toilet.


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Perforation

Colon or Rectum is a serious complication

of the barium enema examination,

occurring in 0.02% to 0.04% of patients.


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Perforation

Extraperitoneal perforation is usually less

catastrophic


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Perforation


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Perforation


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Perforation

Four mechanisms of injury

1) Trauma from the enema tip

2) Overinflation of the balloon3) Recent colonoscopic instrumentation

especially associated with biopsy

4) The presence of rectal mucosal diseasesuch as cancer, stricture, diverticulosis or

inflammatory bowel disease.


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Prevention

Safe tip-balloon design should be used.

Retention balloon should be inflated only

under fluoroscopic monitoring Barium studies should be avoided in

patients with active colitis.


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Prevention

In cases of deep biopsy or polypectomy,

the examination should be delayed by at

least six days.

Generation of pressure greater than that

created by a column of barium suspension

ofone metershould be avoided


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Management

Non-operative approach is safe in small

extra-peritoneal injuries.

Extensive, extraperitoneal extravasation, if

not immediately treated, may cause a peri-

rectal tissue infection and lead to fatal

septicaemic shock within a few hours or

days.


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Less extensive contamination may lead to

pelvic sclerosis with later development of

rectal and ureteric stenosis


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Free intraperitoneal rupture - Rise to a

hypotensive state which can prove fatal.

Adequate resuscitation and early resection or

primary repair and an aggressive effort to

evacuate as much barium as possible are

mandatory.


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Aspiration

Aspiration ofBarium Sulphate can lead to

fatal effect of aspiration pneumonia.

Happen old person and young children- with obstructive/ motility disorders


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Aspiration


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Aspiration Microscopically, most of the particles

accumulate in alveolar spaces and few in the

interstitium.

Inert character does not stimulate inflammatory

reaction unless-

- Acid aspiration

-Barium HD (250 % W/V)


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Aspiration

Hypersensitivity reactions caused by one of the many

additives to commercial

barium preparations can occur .

Barium particles are phagocytized by alveolar

macrophages.

If any fibrotic response occurs - barium sulfate

mixtures act as mechanically obstructive

material leading to emphysema only in rare cases.


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Aspiration- water soluble contrast

media

If a mediastinal fistula is expected Gastrografin

can be used instead of barium sulfate to avoid

mediastinitis.

Can induce pulmonary edema when introduced

directly into normal lungs

Not the material of choice when aspiration is

probable .


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Intravasation

- 0.0040.04% of procedures.

Barium may also intravasate into the venous drainage

of the large bowel and enters the circulation as abarium embolus.

36 cases of barium intravasation have been reported

in thelast 50 years

The British Journal of Radiology (2006)


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Causes

Thinning of the rectal wall with age andproximity of the haemorrhoidal venous plexus

may contribute to intravasation.

Colon affected by disease.

when intraluminal pressure overcomes theresistance of the colonic wall affected by

colitis, diverticulitis or intestinal obstruction.


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Mortality- 26 -60 % more in systemic than portal embolization.


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Prevention

Balloon inflation under fluroscopy

Height of barium column.

Insufflate little air or little barium in start ofprocedure.


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Barium in intestinal obstruction

BMFT is indicated in small bowel

obstruction as there is enough dilution of

barium in small bowel so does not lead to

intestinal obstruction


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Large bowel


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Oral Barium Suftate in Partial Large-Bowel Obstruction - Radiology


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Retained barium in appendix


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Contrast media


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Contrast media

MRIX-ray& CT Scan Ultrasound

Positive

Contrast media

Negative contrast Media

. Air ,Co2

Iodinated Barium

Water based

Oil based

High osmolar

Low osmolar

Gadolinium

compounds etc

Ionic monomer

Ionic dimer

Non ionic monomer

Non ionic dimer


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Basic chemical structure of Iodinated contrast media

Iodine containing benzene ring

Side chains in positions C1-C3-C5 areimportant for the physicochemicalproperties.

C3 determines changes in thesolubility

C5 influences the excretion

R1

R2R3

I

II

1

5

3


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The physicochemical properties of CM play akey role in determining their physiological and

untoward effects: Iodine concentration:

Ionic charge

Hydrophilic properties Viscosity

Osmolality


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Ratio Iodine atomsper molecule

Particles permolecule

Type

3:2 3 2

Ionic monomer

DiatriazoateIothalamate

MetrizoateOsmolality- 1400 2000 mosm/kg water

3:1 3 1 Non Ionic monomer

Iopamidol

Iohexol

Ioversol

Osmolality- 600-800 mosm/kg water

3:1 6 2Ionic Dimer

IoxaglateOsmolality- 600-650 mosm/kg water

6:1 6 1Non Ionic Dimer

IodixanolOsmolality- 320 mosm/kg water

Osmolality of plasma 280 290 mosm/Kg water


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1. Idiosyncratic/ Anaphylactoid Reactions

2. Non Idiosyncratic Reactions

3. Combined Reactions

Contrast Media Reactions

ACR Contrast Media Manual 1991


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1. Estimated that 8 million people receive RCM annually in U.S.

2. Overall frequency of adverse reactions is 5% to 8%

3. Life-threatening reactions occur less than 0.1% with older

(hyperosmolar) agents

4. Mortality estimated at 1 in every 75,000 patients

5. With advent of second generation agents (low-osmolar oriso-osmolar agents) incidence of adverse reactions 1/5 that

of first generation agents

*Neuget AI. Ghatak AT. Miller RL. Anaphylaxis in the United

States: An investigation into its epidemiology.

Archives of Internal Medicine. 161(1):15-21, 2001 Jan 8.

Incidence


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Definition of Terms

Anaphylactoid events vs. Anaphylaxis1. Anaphylaxis: An immediate systemic reaction causedby rapid, IgE-mediated immune release of potentmediators from tissue mast cells and peripheral bloodbasophils.

2. Anaphylactoid events: Immediate systemic reactionsthat mimic anaphylaxis but are not caused by IgE-mediated immune responses

Non Idiosyncratic reactions: Usually dose related


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Possible Mechanisms for Idiosyncratic

Anaphylactoid Reactions


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Minor

Intermediate

Severe

Contrast Reactions


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Contrast Induced Nephropathy

Definition:- Is a condition in which an impairment in

renal function (increase in serum creatinine by 25%

or 44 Qmol /litre) occurs within 3 days following the

intravascular administration of a contrast medium in

the absence of an alternative etiology.

BJR August 2003,513 - 518


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Epidemiology

The percentage of patients at risk 3.5 -15.5%

Depends on presence of a preexisting impaired renal function, diabetes

mellitus, congestive heart failure, and hypertension and on the volume

of contrast used.

Third most common cause of hospital acquired renal failure 10% of

cases

Incidence in general population 2%

Incidence among diabetics 9-40 % Incidence among diabetics with renal insufficiency 50-90%

Ital Heart J 2003; 4 (10): 668-676

AJR: 183, Dec 2004;1673-1689


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10 25 % incidence for a transient need for

dialysis

30 % of pts , renal function fails to touch the

base lineRCNA July 2002


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Renal Handling of Contrast Media

Elimination half life in normal individuals - 2 hrs

75% of administered dose excreted in - 4 hrs

98% of administered contrast excreted in - 24 hrs

Less than 1 % excreted through extra renal route innormal individuals


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Formulas for Dose Calculation


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Mechanism ofContrast InducedNephropathy


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Mechanism of Contrast Induced Nephropathy


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Features

1. Oliguric / Non oliguric renal failure.2. Rise in serum creatinine by 24 hrs and peaks

by 3-5 days .

3. Persistent nephrogram on Radiography or CTscan 24 hrs after procedure.

- immediate dense and persistent nephrogram

- increasingly dense nephrogram.

4. Electrolyte imbalances


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Risk Factors forContrast Induced Nephropathy

AJR: 183, Dec 2004;1673-1689


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Serum creatinine is insensitivemeasurement in patients with normalkidney functions.

More than 50% reduction in GFR may

occur without any increase in serumcreatinine

( BJR- 1998)


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Serum creatinine can be used as an

accurate test in patients with renal

impairment to access any further

deterioration.

Relationship in fall of GFR and rise in serum

creatinine is more helpful after 50% declinein GFR.

( Normal GFR= 125ml/sec)


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Creatinine clearance

-GF

- Tubular secretion

so in general underestimate reduction in

GFR.


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1. Gadolinium K-edge 50.2 Vs 33 Kev iodine ,allows

imaging with a higher Kvp (77- 96).

2. Recommended dose limit 0.3- 0.4 mmol/kgdose for adequate visualization.

3. Best used for selective angiography of small&medium vessels.

(Evaluation of A- V fistulas and veingrafts,aortography ,visceralangiography,genitourinary & biliary studies.

RCNA July 2002

Gadolinium


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Gadolinium

Adverse effects-

Most common side effects - nausea,

emesis & headache.

Incidence 0.4

mmol/kg


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Complications due to embolization

material

E b li ti


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Embolization

Therapeutic introduction of various substancesinto the circulation to occlude vessels, either to

arrest or prevent hemorrhaging, to devitalize a

structure, tumor, or organ

-by occluding its blood supply, or to reduce

blood flow to an arteriovenous malformation


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Embolization may have 3 therapeutic goals

(1) An adjunctive goal- preoperative, adjunct

to chemotherapy or radiation therapy

(2) A curative goal- aneurysms,

arteriovenous fistulae (AVFs), arteriovenous

malformation (AVMs), and traumatic bleeding

(3) a palliative goal- relieving symptoms, such

as of a large AVM


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Material

Coils

Detachable balloons

Small particulate material- polyvinyl alcohol

-gelatin sponge

Liquids- glue

- alcohol and other sclerosants


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Coils

can be grouped into

- Micro coils

-M

acro coils


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Coils

Macro coils - also called Gianturco coils

Advantage - precisely positioned under

fluoroscopic control

Occlusion coil induce thrombosis rather

than mechanical occlusion of the lumen.

Thrombogenic effect increased with

dacron wool tails.


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Coils

Local misplacement

Distal migration.

Collateralization is a potentialdisadvantage of coil embolization

Proximal occlusion occurs with coil

embolization


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Detachable balloons

Premature deflation

Accurate positioning may be difficult to

maintain because of balloon shape.

Principle disadvantage with balloons

multiple catheter exchanges.


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Polyvinyl alcohol

Obtained by the reticulation of PVA (Ivalon) with

formaldehyde.

Supplied in dried state and expands when

comes in contact with liquid.

Histologically - agent causes intraluminal

thrombosis associated with an inflammatory

reaction, with subsequent organization of the

thrombus


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Polyvinyl alcohol

Marketed in various sizes

Non reabsorbable permanent occlusive

agent

(though some recanalization do occur)


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Polyvinyl alcohol

Administered in a mixture of contrast medium

and isotonic sodium chloride solution under

fluoroscopic guidance.

Aggregation of PVA particles can be minimized

by using dilute contrast medium in a matched-

density suspension eg Omnipaque and sodiumchloride solution can be used in a ration of1:0.4

for contour particle suspension.

P l i l l h l


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Polyvinyl alcohol

Complications parallel degree of devascularization

achieved.

Complete infarction is possible using it

however infarction of nontarget tissue can also occur ifcheck angiogram are not performed.

Non radiopaque substances are mixed with contrast

media to see flow pattern.

G l ti (G lf )


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Gelatin sponge (Gelfoam)

water-insoluble, off-white, nonelastic, porous,and pliable material.

May be cut without fraying, and it can absorb

and hold many times its weight in blood.

Acts as a matrix on which thrombus begin to

form and propagate.


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Gelatin sponge

Vascular occlusion is expected to last for 3

weeks.

Partial recanalization followed by complete

recanalization occurs 30 to 35 days.

degree of devascularization achieved with

gelatin is less: so complications are also

less.


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GLUE

Cyanoacrylate- rapidly hardening liquidadhesive.

Substance hardens (polymerizes) immediately

on contact with blood or other ionic fluid.Polymerization results in an exothermic reaction

that destroys the vessel wall.

Foreign body inflammatory reaction is the

primary disadvantage


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Ethanol

Absolute alcohol is the most commonly usedliquid agent.

Has

-a direct toxic effect on the endothelium- causes spasm along length of vessel

Has a potential effect of causing reflux intonon target areas.

Ethanol can be damaging if it reaches the

capillary bed of any given tissue

a1


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Slide 73

a1 that activates the coagulation system and causes the microaggregation of red blood cellsabc, 2/15/2007


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Ethanol

Slow, careful injections by using balloon

occlusion arterial catheters for delivery

By applying manual compression on the

draining veins (or tourniquet control)

or balloon occlusion of the draining system

1 mg/kg is the maximum amount that can be

injected during a single session.

a2


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Slide 74

a2 may decrease alcohol washout from the lesion and reduce acute systemic toxicityabc, 2/15/2007

Complications because of embolization


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Complications because of embolization

Vessels requiring embolization can be broadly

grouped into

Neoplastic vessels.

Arteriovenous communication.

Disrupted vessels with acute hemorrhage.


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Neoplastic vessels

Mainly related to nature of embolic agent .

Proximal occlusion- unlikely to be of any

benefit because of opening up of

collaterals.

Organ failure.


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Arteriovenous communication

Passage of embolic agent through shunt.

-if is on systemic side- eg in post biopsy renal

AV fistula : unlikely to cause major

complication- If shunt is in pulmonary circulation- embolus

may pass into left heart, may lead to disaster.

Di t d l d t


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Disrupted vessel and acute

hemorrhage

Objective is to achieve homeostasis

Non selective embolization should be

avoided as far as possible to avoid

infarction of organs.


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Post embolization syndrome-

Septicemia

Abscess formation. Infarction of embolized organ.

Ulceration in bowel

DIC

a3


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Slide 79

a3 a sequaele of procedure, pain - which usually start during procedure, may last for few days. fever , vomitting are otr features.

paralytic ilabc, 2/16/2007


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Complications of diagnostic

angiography.


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Puncture site-

hematoma

occlusion

pseudoaneurysmAV fistula

contrast extravasation

Non puncture site-

distal emboli

dissection of selected vessel


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Hematoma

Faulty technique: eg puncture above or belowfemoral head in femoral

puncture

Inadequate compression: 20 minute or arterial

10 minutes for venous

Laceration due to large size of needle and

patient coagulation profile.


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Thrombosis

Usually due to catheter: size relative to lumen

type of catheter

length Exposed to blood

Other factors : extent of intimal damage, vascular

spasm, patient coagulation state

Pseudoaneurysm


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Pseudoaneurysm

Pseudoaneurysm is a pulsating Hematomathat results from disruption of a portion of the

arterial wall.

Clotting occurs in the peripheral limits of the

Hematoma, while the center remains fluid and

communicates with the arterial lumen causing a

pulsatile mass.


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Pseudoaneurysm

Right femoral arteriogramDemonstrating Pseudoaneurysm

of SFA


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conclusion

Awareness of complications of a

procedure is the first requirement to

reduce incidence of complications.


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Complicatons in Intervention

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